AU2015313943A1 - Process for making coffee beverages with less bitterness, and apparatus for making Caffe Depurato - Google Patents

Abstract

Disclosed is a method for producing a coffee extract with less bitterness, the method comprising the steps of: a) providing a coffee brewing vessel comprising an intimate mixture of coffee grounds and an aqueous medium; b) reducing the pressure in the coffee brewing vessel so as to be in the range of 3.4 - 84.7 kPa (1-25 inHg); c) brewing the coffee at reflux whilst maintaining the pressure in the range of 3.4 - 84.7 kPa; and d) increasing the pressure in the coffee brewing vessel to atmospheric pressure. Also disclosed is Caffe` Depurato obtained by the above method which has a noticeably improved flavour relative to other conventional brewing processes, and which also possesses less bitterness. Further disclosed is a coffee reflux extraction apparatus comprising: a coffee brewing vessel; a cannula; one or more vacuum pumps for reducing the pressure in the coffee brewing vessel to the range of 3.4 - 84.7 kPa (1-25 inHg); a steam condensing means having an evacuation means; and a collection vessel having a collection vessel evacuation means; wherein the apparatus is configured for the extraction of coffee grounds at reflux for a predetermined time period at a pressure in the range of 3.4 - 84.7 kPa (1-25 inHg); and wherein the apparatus is further configured to subsequently transfer hot liquid from the coffee brewing vessel into the collection vessel via the cannula under the action of a pressure differential provided by one or more of the vacuum pumps and mediated through said evacuation means.

Description

PCT/IB2015/055859 WO 2016/038479 1

Title: Process for Making Coffee Beverages with Less Bitterness, and Apparatus for Making Caffe Depurato

This application claims the benefit of the provisional specifications GB1416209.3 filed on 13 September 2014, GB1416644.1 filed on 22 September 2014, GB1501964.9 filed on 6 February 2015 and GB1507634.2 filed on 5 May 2015 which are all incorporated in their entirety herein by reference.

Field of the invention

The present invention relates to a process for brewing fresh coffee, utilising reduced pressure to control bitter tones and flavours, whilst enhancing the intensity and richness of the coffee, and to thereby produce beverages such as Caffe Depurato. In particular, it has surprisingly been found that coffee which is refluxed in an aqueous medium under reduced pressure and at a temperature substantially below 100°C is extremely pleasant to the taste and is completely unlike coffee which has been boiled at atmospheric pressure for the same period of time. Coffee beverages produced by the process of the present invention have a refined flavour which are generally more preferable in flavour to coffee brewed by traditional methods using hot water with filter funnels, a cafetiere (plunger pot / French Press), an espresso maker etc., even when utilising the same coffee beans, coffee grind size and coffee:water ratio. The invention also provides several novel apparatus for brewing fresh coffee, and which also provides a simple and effective method of brewing the coffee under reduced pressure, as well as being able to separate the resultant coffee from the coffee grounds with minimal intervention by the user.

Background of the invention

There are many methods for the brewing coffee known in the art, and they all provide coffee which differs markedly in its flavour profile / balance, its bitterness, its strength, and its depth of flavour.

At the present time, in western societies, the most common methods of brewing coffee include filter coffee, cafetiere coffee and caffe espresso.

Filter coffee remains very popular as it is a convenient method of brewing fresh coffee that requires minimal effort on the part of the user, and produces reliable and coffee of good quality. Such a brewing process can also be automated. The coffee is usually finely ground, and the water temperature should be just below boiling point. In contrast to coffee brewed in accordance to the present invention, filter coffee has a much less complex flavour and also with increased bitterness. The use of filter paper can also add unwanted flavours to the resultant coffee.

Cafetiere coffee is also a very popular method at the present time. The coffee is usually made by adding water which is just rested from the boil before being added to the coffee, the coffee is then allowed to brew for several minutes before the plunger separates the grinds, and the coffee served. The coffee beans should be ground so as to be coarser than for filter coffee as this requires less physical force to separate the grinds, and this also helps to prevent the coffee from being over-extracted and being excessively bitter. Cafetiere coffee is another simple may of brewing fresh coffee, and is usually slightly richer in taste compared to a PCT/IB2015/055859 WO 2016/038479 2 comparable cup of filter coffee. The coffee is also free from off flavours that can occur from exposure to a filter paper. However, parts of the plunger can sometimes be hard to clean effectively, and there may also be a detectable ’metallic’ flavour due to the contact of hot coffee with some metallic parts of the apparatus. Compared to the coffee of the present invention, when brewed using the same coffee:water ratio, the resultant cup made in a Cafetiere has a noticeable increase in bitterness, is less aromatic, and has significantly reduced depth, it also lacks the refined and sustained lingering flavour often found with coffee prepared in accordance with the present invention.

Espresso coffee makers are also extremely popular, and can be used to produce coffee for a range of beverages such as espresso, cappuccino, Latte, Americano, Mocha, Flat White, Long Black etc. etc.. In this method, coffee is brewed under high pressure, whilst the temperature is kept below 100°C, and typically in the range of 92-96°C. The coffee beans should be very finely ground, and it also uses a relatively high coffee:water ratio than compared for either of the Cafetiere of filter coffee methods. In contrast to coffee brewed in accordance with the present invention, using the same coffee, same grind and coffee:water ratio, espresso coffee has a noticeably increased level of bitterness. Caffe Latte prepared using the process of the present invention was independently found to be more preferable to a comparable cup obtained using a commercial espresso maker. The present invention also facilitates the scale-up preparation of espresso, with it being easy for example, to prepare four cups of high quality espresso simultaneously.

Espresso can also be prepared using stove top espresso makers. These stove top pots can also be used to produce very pleasant coffee beverages. However the results are often quite variable, as the way the coffee grounds are compacted affects the extraction temperature and pressure, and which cannot be controlled accurately. Consequently the results often tend to vary from cup to cup. The results are therefore not usually as reproducible as commercial espresso makers. Again, coffee brewed in accordance with the present invention was generally found to be preferable, and more consistent in quality and flavour.

In recent years the Nespresso® concept has also become increasingly popular. The extraction method utilised by this process is similar to a conventional espresso, but the main advantage comes from the simplicity of the apparatus which is made possible through the use of specially designed prepacked capsules (e.g. such as described in US4136202, US4846052, US5472719 and US7946217 the contents of which are incorporated herein by reference). When coffee is produced by the Nespresso® method, hot water is injected into the capsule under high pressure such as of up to 19 bars. The capsule may also comprise a filter element, and include a frangible portion in order to release the extracted coffee. Although a range of different coffee types and a range of capsules are now on the market, in contrast to the coffee extracts produced in accordance with the present invention; coffee obtained by the Nespresso® method has a noticeable level of bitterness, which is largely absent when coffee is produced from the same capsules and in accordance with the present invention.

Another method of brewing coffee is known as Greek coffee. By this method cold water is added to the ground coffee in a special pot. This is then heated slowly and carefully almost right up to the boiling point. Coffee obtained by this method is generally very strong, and is made with a lot of sugar to contrast the richness and bitterness of the coffee. Turkish Coffee is likewise similar in many regards.

Coffee percolators are also popular for making coffee. The resultant coffee however is generally inferior to PCT/IB2015/055859 WO 2016/038479 3 other prior art methods as the coffee often can become 'stewed' as a result of being brought too close to the boil (at atmospheric pressure). The resultant coffee is often excessively bitter and is often referred to as being over extracted. The coffee can also have a detectable 'metallic' flavour due to the contact of hot coffee with metallic parts of the apparatus.

Another traditional method of brewing coffee which produces a very sought after flavoursome beverage is produced in a cona coffee maker, sometimes referred to as a vacuum pot (and collectively referred to herein as cona coffee). In this method, coffee is typically brewed in a glass apparatus, wherein heated water is allowed to come into contact with the ground coffee without being further heated. The resultant vacuum that forms in the lower flask is then utilised to filter the coffee grounds. The absence of any filter paper or metallic parts produces a much purer flavour, and the absence of excessive heat also produces coffee which has a much more mellow and refined flavour. In contrast to coffee obtained in accordance with the present invention however, the coffee tends not to be as strong or complex in flavour. It is also important to understand that with cona coffee, the coffee grounds themselves are never exposed to and/or extracted under reduced pressure, nor are the coffee grounds directly exposed to boiling water. Relative to the present invention cona coffee still generally has an increased level of bitterness, and is not as refined or smooth in flavour.

Coffee is also known to be brewed using cold extraction techniques such as being described in WO2013/019676, wherein freshly ground roasted coffee beans are cold brewed (at atmospheric pressure) using water which is at a temperature of less than 117°F (47.2 °C). The coffee is then typically brewed for between 18 and 24 hours prior to a filtration step. The flavour profile of a coffee extract prepared in accordance with the present invention shares many similarities to the flavour profile of cold brewed coffee, which is acknowledged to be sweeter to conventionally prepared coffee obtained using hot water on account of its lower acidity. In contrast to cold brew preparation methods such as those described in W02013/01967 however, coffee brewed in accordance with the present invention can be produced in a much shorter time-scale and my be preferable flavour in comparison to cold brewed coffee obtained from the same coffee:water ratio. The process of the present invention also allows the brewing conditions to be tightly controlled, and can be adjusted to a greater degree, thus enabling a beverage to be obtained under predetermined brewing conditions which are selected to meet the demands of the consumer. Coffee prepared in accordance with the present invention is also more versatile and can be used to prepare a much wider range of coffee beverages, and the brewing process of the present invention is also compatible with the inclusion of a range of additives.

Prior to arriving at the present invention, the inventor investigated and developed a method of brewing coffee in a Soxhlet type apparatus, and which utilises a similar principal to coffee percolators. In accordance with a conventional Soxhlet extraction technique the coffee grounds were placed in a Soxhlet thimble, which was then placed within the Soxhlet apparatus (and which thereby defined a brewing vessel). Water in the lower collection flask was then brought to the boil, and the coffee was extracted continuously over a period of several hours at atmospheric pressure. The resulting product however was not very pleasant in taste, and the extraction process was far too time consuming and energy intensive to be practical. In order to improve the Soxhlet process, a new extraction apparatus was designed and which could use a filter paper rather than a Soxhlet thimble, it was also intended to repeat the process under reduced pressure, to improve the efficiency of the continuous extraction process. The new apparatus that was designed corresponds to figure 1 as shown in this specification. This apparatus was also designed to be effective as both an extraction PCT/IB2015/055859 WO 2016/038479 4 apparatus (with coffee grounds being placed above the filter, and the three-way tap used to direct vapour from a lower flask of boiling water direct to a condenser), as well as a vacuum separation apparatus (and as used and discussed herein). In contrast to the present invention, however, a Soxhlet type extraction process requires the coffee grounds to be extracted in intimate contact with a solvent, whilst being located in a brewing vessel which is positioned away from the heat source, and as such, the extraction occurs at a temperature which is significantly below the boiling point of the solvent and results in a weaker extraction so that the solvent has to be recirculated many times. Conventional brewing processes using hot water such as traditional filter coffee, cona vacuum processes, or French press methods are also distinguished from the present invention as the coffee brewing vessel itself is not placed under reduced pressure, and the extraction is also not performed at the water reflux temperature.

The surprising and inventive concept behind the present invention came about whilst exploring other processes to help to optimise and refine the above coffee Soxhlet extraction process. Surprisingly, and most unconventionally, it was found that brewing coffee grounds directly at reflux under reduced pressure could give rise to samples which although having a characteristic bitterness, also had flavour and smoothness that was strangely appealing. It was ultimately the further optimisation and understanding of these samples that gave rise to the present invention.

In view of the above, whilst many alternative methods of making coffee are known in the art, many processes brew the coffee in such a way that bitter flavours are absorbed and incorporated into the beverage. The high temperatures used in many of the traditional brewing processes also inevitably thermally decompose some of the complex organic compounds present in the coffee, and impart additional unwanted / unpleasant flavours to the coffee. It is therefore an object of the present invention to go some way to overcoming the above-noted deficiencies in this art; and/or to at least provide the public with a useful choice.

In this specification where reference has been made to patent specifications, other external documents, or other sources of information, this is generally for the purpose of providing a context for discussing the features of the invention. Unless specifically stated otherwise, reference to such external documents is not to be construed as an admission that such documents, or such sources of information, in any jurisdiction, are prior art, or form part of the common general knowledge in the art.

Summary of the invention {A}: In one aspect, the present invention provides a method for producing a coffee extract, the method comprising the steps of: a) providing a coffee brewing vessel comprising an intimate mixture of coffee grounds and an aqueous medium; b) reducing the pressure in the coffee brewing vessel so as to be in the range of 3.4 - 84.7 kPa (1-25 inHg); c) brewing the coffee at reflux whilst maintaining the pressure in the range of 3.4 - 84.7 kPa; and d) increasing the pressure in the coffee brewing vessel to atmospheric pressure. {B}: The present invention further provides the method of {A}, wherein the method is for producing a coffee extract with less bitterness, wherein at least some of the compounds that impart bitterness are selectively thermally degraded and/or chemically reacted. {C}: The present invention further provides the method of {A} or {B}, wherein prior to step c), the PCT/IB2015/055859 WO 2016/038479 5 method further comprises a step b’) of heating the contents of the coffee brewing vessel whilst maintaining the pressure in the range of 3.4 - 84.7 kPa (1-25 inHg). {D}: The present invention further provides the method of any one of {A}-{C}, wherein the pressure in the coffee brewing vessel is preferably in the range of 13.5 - 67.7 kPa (4-20 inHg), more preferably between 23.7 kPa and 50.8 kPa (between 7 and 15 inHg), and most preferably between 27.0 and 40.6 kPa (10 ± 2 inHg). {E}: The present invention further provides the method of any one of {A}-{D}, wherein after step c) but prior to and/or during step d) the extracted coffee grounds are separated from the extracted aqueous medium. {F}: The present invention further provides the method of any one of {A}-{D}, wherein the extracted coffee grounds are separated from the extracted aqueous medium only after step d). {G}: The present invention further provides the method of any one of {E} or {F}, wherein the extracted coffee grounds are separated from the extracted aqueous medium by a process of vacuum separation. {H}: The present invention further provides the method of any one of {A}-{G}, wherein prior to step a) the coffee grounds are obtained by freshly grinding roasted coffee beans. {I}: The present invention further provides the method of any one of {A}-{G}, wherein prior to step a) the coffee grounds are provided in the form of a substantially anhydrous prepackaged coffee product, which optionally further comprises one or more additives. {J}: The present invention further provides the method of {I}, wherein the prepackaged coffee product is intended to be consumed in a single extraction process for preparing a single coffee beverage, and comprises between 5 and 18 grams of coffee grounds. {K}: The present invention further provides the method of any one of {A} to {J}, wherein the method is performed such that the coffee extract and/or the coffee grounds are not exposed to a temperature in excess of 80°C, and preferably not in excess of 75°C. {L}: The present invention further provides the method of any one of {A} to {K}, wherein in step a) the coffee grounds and the aqueous medium are provided in a weight ratio of from 1:2.78 to 1:50. {M}: The present invention further provides the method of {L}, wherein the ratio ranges from 1:25 to 1:50, preferably from 1:28 to 1:38. {N}: The present invention further provides the method of claim {L}, wherein the ratio ranges from 1:2.78 to 1:10, preferably from 1:5.8 to 1:6.8. {O}: The present invention further provides the method of any one of {A}-{N}, wherein step c) is sustained for a period of time between 10 seconds and 30 minutes, more preferably between 1 and 5 PCT/IB2015/055859 WO 2016/038479 6 minutes, and most preferably at 2 minutes ± 30 seconds; and wherein commencement of the period of time is determined from the point at which the aqueous medium reaches its water reflux temperature. {P}: The present invention further provides the method of any one of {A}-{0}, wherein the coffee brewing vessel during step c) further comprises one or more additives. {Q}: The present invention further provides the method of {P}, wherein the one or more additives are selected from the group consisting of milk, including fresh milk, UHT milk or cold pasteurised and/or filtered milk; milk powder; cocoa; chocolate; natural sweeteners, including refined, unrefined or partially refined sugar; synthetic sweeteners; flavour enhancers; flavourants, including flavoured syrups; essential oils; fruit juice; fruit pieces; herbs; spices; vitamins; minerals; pharmaceutically active compounds; preservatives; colourants; thickeners; foaming agents and combinations thereof; and wherein the one or more additives are more preferably selected from the group consisting of refined, unrefined or partially refined sugar; chocolate; cocoa; vanilla; salt; cinnamon; orange oil or orange peal. {R}: The present invention further provides the method of any one of {A}-{Q} wherein the coffee grounds, the coffee extract and the aqueous medium are not placed in contact, or able to make contact with any metal objects during the performance of the method. {S}: The present invention further provides the method of any one of claims {A}-{R} wherein the method is either partially or completely automated. {T}: The present invention further provides a method of making a coffee extract comprising: brewing at reflux in a coffee brewing vessel, an intimate mixture comprising coffee grounds and an aqueous medium, wherein the pressure in the coffee brewing vessel is pumped down into the range of 3.4 - 84.7 kPa (1-25 inHg). {U}: The present invention further provides the method of any one of {A}-{T} wherein the pressure in the coffee brewing vessel is achieved utilising a hand operated vacuum pump, or an automated and/or electrically powered vacuum pump. {V}: The present invention further provides the method of any one of {A}-{U} wherein during the brewing step, a substantial portion of any condensable vapours that leave the coffee brewing vessel are condensed utilising an external source of water or air, and the resultant condensate is allowed to return back to the coffee brewing vessel. {W}: The present invention further provides a coffee extract with less bitterness obtained and/or obtainable by the method of any one of claims {A}-{V}. {X}: The present invention further provides the use of the coffee extract with less bitterness according to {W}, for making a coffee beverage, for making a food product, or for making a dried instant-coffee product. {Y}: The present invention further provides a coffee reflux extraction apparatus comprising: a coffee brewing vessel; a cannula; one or more vacuum pumps for reducing the pressure in the coffee brewing PCT/IB2015/055859 WO 2016/038479 7 vessel to the range of 3.4 - 84.7 kPa (1-25 inHg); a steam condensing means having an evacuation means; and a collection vessel having a collection vessel evacuation means; wherein the apparatus is configured for the extraction of coffee grounds at reflux for a predetermined time period at a pressure in the range of 3.4 - 84.7 kPa (1-25 inHg); and wherein the apparatus is further configured to subsequently transfer hot liquid from the coffee brewing vessel into the collection vessel via the cannula under the action of a pressure differential provided by one or more of the vacuum pumps and mediated through said evacuation means. {Z}: The present invention further provides a coffee reflux extraction apparatus comprising: a coffee brewing vessel; a cannula; one or more vacuum pumps for reducing the pressure in the coffee brewing vessel to the range of 3.4 - 84.7 kPa (1-25 inHg); a steam condensing means having an evacuation means; a filter vessel having a filter and at least one filtrate outlet for connection to a collection flask; wherein the filtrate outlet further comprises a filtrate evacuation means; and wherein the coffee brewing vessel and the cannula are configured to transfer an aqueous medium contained in the coffee brewing vessel to the filter vessel via the cannula under the action of a pressure differential provided by one or more of the vacuum pumps and mediated through said evacuation means. {AA}: The present invention further provides a coffee reflux extraction apparatus according to {Y} or {Z}, wherein the distance between the bottom of the cannula and the lowest inside surface of the coffee brewing vessel is 1500 micrometres (microns) or less, and preferably 500 micrometres ±300 micrometres. {AB}: The present invention further provides a coffee reflux extraction apparatus according to any one of {Y}-{AA}, wherein the evacuation means and filtrate evacuation means can be pressure equalised under reduced pressure. {AC}: The present invention further provides a coffee reflux extraction apparatus according to any one of {Y}-{AB}, wherein the steam condensing means further comprises a gas inlet that allows the pressure in the coffee brewing vessel to be increased. {AD}: The present invention further provides a coffee reflux extraction apparatus according to any one of {Y}-{AC}, wherein polytetrafluoroethylene (PTFE) is used to minimise any leaks between joints of the coffee reflux extraction apparatus. {AE}: The present invention further provides a coffee reflux extraction apparatus according to any one of claims {Y}-{AD}, wherein the apparatus is free of any metal parts or components which may impart undesirable flavours to the coffee extract. {AF}: The present invention further provides a method of any one of {A}-{V}, wherein the method is performed in the coffee reflux extraction apparatus as defined in any one of {Y}-{AE}. {AG}: The present invention further provides a coffee reflux extraction apparatus for performing the method of any one of {A}-{V}, wherein the apparatus comprises: a coffee brewing vessel in communication with a heat source; a steam condensing means; and a vacuum pump; wherein the apparatus is configured to sustainably condense water vapour in the temperature range of between 25 and 95°C for at least 90 seconds, PCT/IB2015/055859 WO 2016/038479 8 and to provide a means for returning the condensed water back to the coffee brewing vessel. {AH}: The present invention further provides a coffee reflux extraction apparatus when used to perform a method of making a coffee extract; wherein the method comprises: brewing at reflux in a coffee brewing vessel, an intimate mixture comprising coffee grounds and an aqueous medium, wherein the pressure in the coffee brewing vessel is pumped down into the range of 3.4 - 84.7 kPa (1-25 inHg). {Al}: The present invention further provides the coffee reflux extraction apparatus according to {AH}, wherein the apparatus comprises: a coffee brewing vessel in communication with a heat source; a steam condensing means; and a vacuum pump; wherein the apparatus is configured to sustainably condense water vapour in the temperature range of between 25 and 95°C for at least 90 seconds, and to provide a means for returning the condensed water back to the coffee brewing vessel. {AJ}: The present invention further provides the use of a coffee reflux extraction apparatus in a method of producing a coffee beverage, wherein the method comprises: brewing at reflux in a coffee brewing vessel, an intimate mixture comprising coffee grounds and an aqueous medium, wherein the pressure in the coffee brewing vessel is pumped down into the range of 3.4 - 84.7 kPa (1-25 inHg).

Aims of the present invention

In view of the various disadvantages inherent to the prior art, the present invention aims to provide a method of brewing coffee which has an improved and enhanced richness of flavour, and which is both intense and mellow, and yet being devoid of unpleasant bitterness.

Another aim of the present invention is to provide coffee beverages, wherein at least some of the compounds that impart bitterness are selectively thermally degraded and/or chemically reacted without substantially altering the overall chemical profile and/or the flavour balance of the coffee extract.

Another aim of the invention is to provide a coffee brewing method with an extremely tight control over the brewing temperature. This is achieved by performing the brewing step at the water reflux temperature, and using reduced pressure to thereby accurately and precisely control the brewing temperature.

Another aim of the present invention is to provide a coffee extraction apparatus for carrying out the process of the present invention, wherein the apparatus comprises: a coffee brewing vessel in communication with a heat source; a steam condensing means configured to condense water vapour in the temperature range of between 25 and 95°C, and to return condensed water to the coffee brewing vessel; and a vacuum pump.

Another aim of the present invention is to provide a coffee extraction apparatus comprising: one or more vacuum pumps for reducing the pressure in the apparatus to the range of 3.4 - 84.7 kPa (1-25 inHg); a coffee brewing vessel; a cannula; a steam condensing means having an evacuation means; a filter vessel having a filter and at least one filtrate outlet for connection to a collection vessel; wherein the filtrate outlet further comprises a filtrate evacuation means; and wherein the coffee brewing vessel and the cannula are configured to enable an aqueous medium contained in the coffee brewing vessel to be transferred to the filter vessel by means of the cannula under the action of a pressure differential provided by one or more of WO 2016/038479 PCT/IB2015/055859 9 the vacuum pumps.

Another aim of the present invention is to provide a coffee brewing apparatus which allows for coffee to be brewed at reflux under reduced pressure, whilst also providing for a simple and effective means for separating the resultant coffee extract from the coffee grounds.

Another aim of the present invention is to provide a freshly brewed coffee extract with less bitterness, which is obtained by the process of the invention.

Another aim of the present invention is to provide a dried instant coffee product which is obtained from the coffee extract with less bitterness.

Description of the figures

Figure 1 shows a novel vacuum separatory apparatus which can also be used in accordance with the present invention.

Figure 2 shows a novel apparatus which enables the coffee to be brewed in accordance with the present invention, and which further enables the resultant coffee to be quickly and effortlessly vacuum separated whilst the coffee is still hot.

Figure 3 shows another novel apparatus which enables the coffee to be brewed in accordance with the present invention, and which further enables the resultant coffee to be vacuum separated whilst the coffee is still hot. Such an apparatus is also intended to be easy to disassemble and clean after use.

Figure 4 shows an alternative design to the apparatus of figure 3, and which has a separate water inlet, and which is also designed to enable the coffee brewing vessel to be evacuated faster, and without the need to place the entire apparatus under reduced pressure during the brewing step.

Figure 5 shows a more compact and refined apparatus for performing the process of the present invention, and which allows the vacuum separated coffee extract to be poured directly into a coffee cup.

Figure 6 shows a cross-section through parts of the apparatus presented in figure 5.

Figure 7, shows the ATR - FTIR analysis of coffee extracts obtained by different extraction methods, using a commercial brand of espresso ground coffee (illy caffe (Italy)) (intended for espresso machines / fine grind / dark roast).

Figure 8 shows the ATR - FTIR analysis of coffee extracts obtained by different extraction methods, using freshly ground commercial coffee beans ("nectar” - Hummingbird coffee (Christchurch, New Zealand)) (hand ground to provide a wide particle size distribution) (as herein designated as ”HB”).

Figure 9 shows the ATR - FTIR analysis of coffee extracts obtained by different extraction methods, using another commercial source of ground coffee ("Brew” - Caffe L’affare Limited / (Wellington, New Zealand)) ("Plunger or Filter Grind”) (as herein designated as "CL”).

Figure 10 shows the ATR - FTIR side by side comparison of the three different commercial sources of roasted coffee, having different particle sizes, and particle size distributions, when brewed utilising the method of the present invention. PCMB2015/055859 WO 2016/038479 10

Detailed description of the invention

In the description in this specification reference may be made to subject matter which is not within the scope of the claims of the current application. That subject matter should be readily identifiable by a person skilled in the art and may assist in putting into practice the invention as defined in the claims of this application.

Throughout the description and claims, the terms "comprise”, "comprises”, "comprising”, "comprised” and the like, are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense, that is to say in the sense of "consisting at least in part of’. When interpreting each statement in this specification that includes the term "comprises”, features other than that or those prefaced by the term may also be present. Related terms such as "comprise”, "comprising” and "comprised” are to be interpreted in the same manner.

As used herein, the term "coffee” is taken to encompass a product derived from the beans of the coffee plant, and which includes both Arabica coffee and Robusta coffee. The present invention is particularly directed towards an extraction process which is applied to roasted coffee beans as opposed to an extract obtained from green or unroasted coffee beans.

As used herein, the term "water reflux temperature” is defined as the temperature at which water in a vessel boils and can begin to reflux, and which is dependent upon the prevailing pressure in the vessel. At 0.483 bar (14.3 inHg / 48.3 kPa) for instance, the water reflux temperature would be at approximately 80°C.

As used herein the terms "reflux” and "refluxing” are to be construed as relating to a process, wherein a liquid is boiled and wherein a substantial portion (typically at least 50% by weight, and most preferably in excess of 90% by weight) of the vapours are condensed and are able to be returned back to the vessel of boiling liquid. It is most preferred that substantially all of the moisture is able to be condensed so as to prevent moisture from entering into the vacuum pump. It is also most preferable that the reflux is performed in conjunction with an efficient steam condensing means; in this way the condensed water being of high purity, is also able to rapidly adsorb volatile coffee components that would otherwise be lost, thus helping to maintain a significant proportion of the aroma constituents in the coffee extract. It is also particularly preferred that the coffee is boiled intensively under reflux conditions, such that the fluid in the coffee brewing vessel initially has a characteristic appearance of a boiling foam, wherein the foam layer has a depth of at least 0.5 cm, and which is prevalent across the whole of the upper surface of the boiling liquid, and whereby as soon as the pressure in the coffee brewing vessel is increased in step d) the boiling of the fluid in the coffee brewing vessel is immediately halted, resulting in a liquid which is completely free of bubbles, foam, scum or crema. It is preferable to calculate the brewing time from the point at which the water reflux temperature has been reached. The water reflux temperature typically being said to have been reached when the coffee brewing vessel reaches a thermal equilibrium, and/or when the contents of the coffee brewing vessel have the appearance of a boiling foam with a foam layer being of at least 0.5 cm in depth and which is prevalent across the whole surface of the boiling liquid. The phrase "thermal equilibrium” refers to the situation whereby the temperature in the coffee brewing vessel becomes essentially static as heat is rapidly lost from the coffee brewing vessel on account of the aqueous medium being at its boiling point. Whilst almost any liquid can be boiled in an open vessel at atmospheric pressure, in contrast, PCT/IB2015/055859 WO 2016/038479 11 and in accordance with the present invention the aqueous medium must be refluxed under reduced pressure but with an accompanying condensation of the released moisture and coffee volatiles. When brewed under reduced pressure, if the vapours are not condensed efficiently, and are instead just subjected to boiling, the pressure and temperature within the apparatus cannot be accurately controlled, and the pressure and temperature may disadvantageously rise quickly, and/or the vacuum pump can become flooded, and/or the aqueous medium is rapidly lost, along with many of the volatile coffee flavours and aromas. It should also be emphasised that the process of the present invention does not encompass a process which is open to air, even if it could be performed at some geographic locality / altitude such as boiling coffee at the summit of a mountain. The sudden reduction in pressure from the prevalent atmospheric pressure is also an important feature of the present invention as it ensures that the grounds are extracted optimally without being released prematurely. The sudden drop in pressure combined with being brought to reflux greatly facilitates the release of volatile components, carbon dioxide and air from deeper within the coffee grinds whilst greatly increasing their porosity. The extraction process of the present invention thereby provides a more consistent extraction which is achievable regardless as to the coffee grind size and particle size distribution.

As used herein, the phrase "reduced pressure” unless the context unambiguously demands otherwise, refers to a partial vacuum, meaning that the pressure is less than atmospheric pressure. In the priority documents, the term "vacuum” is often used interchangeably to have the same intended meaning as 'reduced pressure’, rather than referring to an absolute vacuum; i.e. a phrase referring to 'placing the apparatus under vacuum’, is intended to have the exact same meaning as 'placing the apparatus under reduced pressure’ and visa versa. Similarly, a phrase such as 'the vacuum was removed’ is to be conveyed as having the same meaning as 'the pressure was increased to atmospheric pressure’.

As used herein, the term "coffee brewing vessel” defines the part of an apparatus where the coffee extraction process takes place, and thereby provides the means by which the coffee grounds and the aqueous medium are maintained in intimate contact as the extraction proceeds at the water reflux temperature.

As used herein, the phrase "an intimate mixture of coffee grounds and an aqueous medium” refers to a slurry of ground coffee particulates which are immersed in the aqueous medium, such that heat can be efficiently transferred from the aqueous medium, into and within the coffee particulates, and such that the aqueous medium is simultaneously able to dissolve any soluble coffee constituents that can be released from within the ground coffee particulates.

As used herein, the phrase "a coffee extract with less bitterness” is to be construed as relating to a coffee extract that is less bitter and less astringent to the taste than a corresponding comparative coffee extract that is obtained by placing the same batch of coffee grounds in contact with an aqueous medium at a temperature of 90°C or greater at atmospheric pressure, for the same period of time. A coffee extract with less bitterness obtained in accordance with the process of the present invention is therefore less bitter and less astringent to the taste than a coffee extract produced by conventional hot extraction processes utilising for instance a French press, a filter cone, or an espresso machine.

As used herein the term "evacuation means” is defined as a means which enables gas and/or vapour to be transferred from one part of the apparatus towards a vacuum pump. In its simplest form the "evacuation PCT/IB2015/055859 WO 2016/038479 12 means” may take the form of a tube or pipe connected to a vacuum pump. The "evacuation means” may also further comprise one or more valves and/or taps to facilitate the transfer of gas and/or vapour in a single direction.

As used herein the term "steam condensing means” is to be construed as relating to the part or parts of the apparatus which are able to condense a substantial portion (typically at least 50% by weight, and more preferably in excess of 90% and even more preferably in excess of 95%) of the vapour that exits the coffee brewing vessel during the brewing step, the predominant volatile component of the vapour being steam. When an efficient steam condensing means is utilised, condensed water being of high purity, is also able to rapidly adsorb volatile coffee components that would otherwise be lost, thus helping to maintain a significant proportion of the aroma constituents in the coffee extract. A wide range of suitable components are known in the pharmaceutical and petrochemical industries for such purposes. In a preferred embodiment, the "steam condensing means” is preferably made from a material such as glass or stainless steel. The "steam condensing means” may also include a suitable coolant, or else it may use the temperature of the ambient air to bring the condensation process into effect, wherein if a coolant is used, it may either flow continuously through the "steam condensing means”, or else it may be static. The "steam condensing means” is most preferably of a type selected from a glass dewar condenser (which can be left empty or else the cold finger can be filled with cold water or ice-water), or an efficient air-condenser such as a vigreux column or a Findenser (e.g. a Radleys Heidolph Findenser super air condenser); only these types of efficient condensers can be said to be configured to sustainably condense water vapour in the temperature range of between 25 and 95°C, particularly for at least 90 seconds, and to thereby provide a means for returning the condensed water back to the coffee brewing vessel. Alternatively the "steam condensing means” may take the form of a tube made of either glass or stainless steel which is designed and able to dissipate the heat from the vapour, such a tube may be coiled, and may optionally include one or more fins to help dissipate the heat. For the sake of simplicity and ease of maintenance, the "steam condensing means” preferably does not require any special coolant, and also does not require a continuous water supply, particularly as the reflux / brewing time is typically relatively short.

As used herein, the term/phrase "vacuum separation” is defined as a process wherein coffee grinds are separated from the extracted aqueous medium under the application of a pressure gradient, wherein the force of pressure exerted onto the separated aqueous medium is less than the force exerted by atmospheric pressure, and wherein the force of pressure exerted onto the separated aqueous medium is less the force of pressure exerted onto the coffee slurry which is to be separated. In addition to the applied pressure differential, a vacuum separation step may be performed using any conceivable apparatus known to a person skilled in the art, and which may for instance comprise any physical separation method, such as through the use of a filter, or by a step comprising passing the coffee slurry through a narrow gap which is able to remove a substantial portion of grounds from the aqueous medium. A filter may for instance have a mesh ranging in size from between about 37 micrometers (400 mesh) and about 400 micrometers (40 mesh), and preferably between about 70 micrometers (200 mesh) and about 180 micrometers (80 mesh), and most preferably from about 125 micrometers (120 mesh) to about 150 micrometers (100 mesh). As used herein, the term "vacuum separatory apparatus” relates to an apparatus which is intended to perform the process of vacuum separation.

As used herein the term "aqueous medium” is defined as a medium which forms the main extraction PCT/IB2015/055859 WO 2016/038479 13 solvent during the brewing / coffee extraction step, and which comprises water in excess of 55% by weight, more preferably in excess of 90% by weight. In most instances the aqueous medium is simply good quality drinking water, such as filtered water, and being substantially free (i.e. except allowing for natural levels of intrinsic impurities) of other solvents such as ethanol etc., and also being substantially free (i.e. except allowing for natural levels of intrinsic impurities) of organic salts and metal salts. In other instances however the aqueous medium can include, or can be selected from fresh milk, fruit juice, alcoholic beverages, sugar syrups etc. and mixtures thereof. The aqueous medium is usually introduced into the coffee brewing vessel in liquid form, however it may also be introduced in the form of a solid (e.g. ice) or in vapour form (i.e. steam).

Conventional knowledge in the art of brewing coffee teaches that fresh coffee should not be exposed to boiling water or else it becomes over extracted, having a characteristic bitter taste caused at least in part due to the presence of excessive amounts of polyphenols. In particular, conventional methods and/or known steps for making coffee less bitter include: a) altering the degree of roasting of the beans (medium roasted coffee has less soluble solids, a higher acid content, and a potent aroma when compared to darkly roasted coffee); b) decaffeination slightly reduces the perceived coffee bitterness; c) allowing coffee to soak in fresh water for approximately twenty-four hours after the fermentation process is said to reduce coffee bitterness (as often performed in Kenya); d) brewing via a drip system (i.e. filter coffee) reduces coffee bitterness relative to French press or other soaking methods, largely as a consequence of decreasing the amount of soluble solids - which has been positively correlated with bitterness; and/or e) using a coarser grind setting to reduce the coffee bitterness (on account that the lower surface area reduces the overall effectiveness of the extraction process). Accordingly, conventional wisdom therefore dictates that highly extracted and purposefully boiled coffee would be highly unattractive and undesirable. One of the methods of making coffee that gets closest to a ’boiled’ coffee is Greek coffee. Greek coffee is indeed as you might expect quite bitter in taste, and is generally taken with a lot of sugar.

The present invention is founded on the surprising discovery that roasted and ground coffee which is brewed by intensively boiling coffee for a period of time under reduced pressure has a distinctly different taste to coffee which is boiled at atmospheric pressure. Without wishing to be bound by theory, it is thought that the act of bringing coffee to the boil under reduced pressure forces volatile organic compounds and moisture contained deep within the coffee grains to expand and be released, thus significantly increasing the porosity of the coffee grains, relative to other extraction methods known from the prior art and as discussed above. At temperatures below 95°C, preferably below 80°C, and ideally around 70°C, the conditions are also not believed to be sufficiently harsh so as to thermally decompose many of the complex organic compounds found within the coffee (including compounds such as caffeine, cafestol and kahweol). It also appears that the dipole moment of water changes under conditions of temperature and pressure, such a change accordingly effects the solvation capability of the water. At lower temperatures and pressure, water appears to lack the solvation capability to solubilise many of the polyphenols which often give coffee its bitterness. The effect of bringing the water to the boil also provides a beneficial agitation to the ground coffee whilst simultaneously providing large amounts of energy to the water in order to solubilise a larger proportion of compounds than can be achieved by other prior art methods. It has also been found that coffee brewed in accordance with the present invention is much less affected by the size of the coffee grind than as observed with traditional methods of the prior art. In particular the inventor has found that coffee of comparable strength and flavour is obtained using a wide range of grind sizes when boiled under the same conditions. PCT/IB2015/055859 WO 2016/038479 14

This thereby provides greater consistency to the resultant coffee, and enables cheaper coffee grinders which are less consistent in grind size to be utilised without any appreciable difference in the end product.

Roasted coffee beans are a very complex food product which contains well over a thousand separate chemicals. Some of the key chemical compounds which contribute to the bitterness associated with coffee include compounds such as 5-hydroxymethylfurfural, 2-methyl-furan, furfuryl alcohol, trigonelline, chlorogenic acid, caffeic acid, quinic acid and its derivatives, citric acid, malic acid, lactic acid, pyruvic acid, acetic acid, pyrazine, thiazole, quinoline, 3-phenyl-pyridine, a range of aIkyl-pyridines, caffeine, several peptides and proteins, as well as a range of alicyclic and aromatic ketones. The inventor has perceived that many of the compounds which induce bitterness are reactive and unstable, and the inventive process also aims to selectively consume many of these reactive compounds during the brewing process. In particular, it is believed that by intensively brewing coffee under reduced pressure in accordance with the present invention, several of the compounds which can give coffee its bitter and astringent taste are subject to reaction, such as by way of condensation reactions, polymerisation reactions and/or decarboxylation reactions. In a similarly way, it is also believed that the amount of the carcinogenic compound acrylamide (often found in coffee beverages of the prior art) may also be reduced. In accordance with the present invention, and in direct contrast to prior art methods, one of the aims of the present invention is to provide coffee beverages, wherein at least some of the compounds that impart bitterness are selectively thermally degraded and/or chemically reacted without substantially altering the overall chemical profile and/or the flavour balance of the coffee extract. In effect the coffee is to some extent purified, and relieved of its bitterness and is in essence Caffe Depurato.

Further to the above, during the reduced pressure reflux brewing step of the present invention, a significant amount of carbon dioxide is released. Under such conditions it is perceived that compounds such as quinic acid and chlorogenic acid undergo a decarboxylation reaction analogous to the process presented by Ran, N et al. (see for instance the reaction in Scheme 3 of J. Am. Chem. Soc., 2001, Vol. 123(44), pl0927). Irrespective as to the exact mechanistic action and reactivity that underlies the present inventive extraction process, the reaction products present in the coffee brewing vessel at the end of the brewing step appear to have more tolerable flavours (e.g. esters and polyols rather than acids and aldehydes), and/or have reduced solubility and are therefore removed with the grinds during a subsequent separation or filtration step.

Coffee brewed in accordance with the present invention has a relatively high alkaloid concentration relative to traditionally filtered coffee, as the extraction process is more effective than using conventional means of brewing coffee. In addition to caffeine, coffee produced in accordance with the present invention is also believed to have greater amounts of the alkaloids cafestol and kahweol which are both known to have beneficial antioxidant and anticarcinogenic properties. A small amount of white residue attributed to some of these alkaloids for instance can often be observed on the sides of the cooled coffee brewing vessel. However, it may not always be preferable to produce a beverage having high amounts of the alkaloids cafestol and/or kahweol; therefore depending upon the choice of coffee slurry separation method the amount of these alkaloids may be controlled to some extent. The use of filter paper rather than a metal gauze or mesh during a filtration step is one such means reported in the art for reducing the amount of cafestol and/or kahweol in the beverage. In the absence of any additional ingredients, coffee brewed in accordance with the present invention and filtered using a French press for instance may include a considerable amount of sediment, but nevertheless the coffee maintains a smooth, rich flavour with PCT/IB2015/055859 WO 2016/038479 15 noticeable hints of chocolate despite only whole milk being added to the final beverage. In accordance with the present invention, if a filtration step is used, the filter may for instance have a mesh ranging in size from between about 37 micrometers (400 mesh) and about 400 micrometers (40 mesh), and preferably between about 70 micrometers (200 mesh) and about 180 micrometers (80 mesh), and most preferably from about 125 micrometers (120 mesh) to about 150 micrometers (100 mesh).

Figure 1 shows a setup which can be used to vacuum separate the coffee once it has been brewed in accordance with the present invention. The receiving vessel (100) is fitted with a three way T-bore tap (101) such as being made of glass or polytetrafluoroethylene, and the collection vessel (102) has only a single inlet / outlet. It is also generally preferable to have a removable funnel (103) fitted to the top of the receiving vessel (100). Without limitation, the filter (104) is preferably in the form of a fine stainless steel mesh, a sintered glass disc, or a perforated glass disc onto which a small pre-washed filter paper can be placed. Tap (101) is initially put in the open position such that all three outlets are simultaneously open. The brewed coffee and coffee grounds can then be poured into the receiving vessel. Funnel (103) is then removed, and a vacuum pump connected in its place. Still with tap (101) in the fully opened position, the pressure in the apparatus can be reduced. Once the pressure has been suitably reduced (typically between 10-25 inHg / 33.9-84.7 kPa), tap (101) is turned such that the side arm is closed off, and only the path from the filter (104) to the collection vessel (102) remains open. The pressure is then increased such that the receiving vessel (100) is allowed to come back to atmospheric pressure. As this happens, the lower pressure in the collection vessel (102) quickly draws the hot freshly brewed coffee through the filter, and down into the collection vessel (102). Upon completion of the process, it is generally advisable to turn the tap (101) back to the fully open position so as to release any residual vacuum. At this point more coffee can be added, and the above vacuum separation process repeated as necessary.

Figure 2 shows a novel apparatus which enables the coffee to be brewed in accordance with the invention and which further provides for a convenient method for vacuum separating the resultant coffee without the need to first bring the brewed coffee up to atmospheric pressure; i.e. prior to and/or during step d of the inventive process, this apparatus enables the coffee to be vacuum separated. Such an apparatus accordingly saves time and energy relative to independently performing separate brewing and coffee grounds separation steps. The coffee extraction apparatus comprises as the main components: one or more vacuum pumps for reducing the pressure in the apparatus to the range of 3.4 - 84.7 kPa (1-25 inHg); a coffee brewing vessel (105); a cannula (106); a steam condensing means (107) having an evacuation means (108); a filter vessel (100) having a filter (104) and at least one filtrate outlet (109) for connection to a collection vessel (102); wherein the filtrate outlet further comprises a filtrate evacuation means (110); and wherein the coffee brewing vessel (105) and the cannula (106) are configured to enable an aqueous medium contained in the coffee brewing vessel to be transferred to the filter vessel (100) by means and of the cannula under the action of a pressure differential provided by one or more of the vacuum pumps. Initially, coffee grounds and water are placed in the coffee brewing vessel (105), which is connected to the main body of the apparatus through pressure joint (111), and placed in contact with a suitable heating unit. Evacuation means (108) provides a means of evacuating the steam condensing means and coffee brewing vessel (105), whilst filtrate evacuation means (110) provides a means of evacuating the collection vessel (102) and filtrate outlet (109). Between the various joints of the apparatus it is also preferable to use polytetrafluoroethylene (PTFE / Teflon®) sleeves (112) to help maintain the reduced pressure in the system as well as to ensure the glass joints are easy to separate and are free of grease and other contaminants. During the brewing process, PCT/IB2015/055859 WO 2016/038479 16 it is preferable for evacuation means (108) and filtrate evacuation means (110) to be pressure equalised, whereby a vacuum pump is connected through vacuum outlet (113). The steam condensing means (107) may also be of a type similar in operation to a Dewar condenser which includes a cold finger (114) so as to make the vapour condensation more efficient, rather just relying upon the walls of the apparatus to provide for vapour condensation alone. The apparatus can be designed such that a coolant such as water can be circulated through the apparatus, however as the brewing period is often relatively short, it is usually more convenient to provide the apparatus with a cold finger (114) in the form of a reservoir whereby coolant can be added through coolant inlet (115). In a further embodiment, the apparatus further comprises a gas inlet (116), that allows the pressure inside the steam condensing means (107) and/or coffee brewing vessel (105) to be increased. After the brewing stage has been completed, it is preferable to increase the pressure in the coffee brewing vessel (105) through gas inlet (116), such that the brewed coffee and coffee grounds can be transferred through to the filter vessel (100) by means of cannula (106); the filtration step then immediately starts to commence utilising the residual vacuum, and without the need to first isolate the extract contained in the coffee brewing vessel at atmospheric pressure. Because of the proximity of the cannula opening to the bottom of the coffee brewing vessel, (106) itself enables much of the coffee grounds to remain in the coffee brewing vessel and which also helps to speed up the overall vacuum separation step, in this way the vast majority of the coffee grounds are initially vacuum separated before the aqueous coffee extract is passed through to the filter vessel. Utilising filtrate evacuation means (110) any coffee grounds which have been transferred into the filter vessel (100) can then easily be separated on the filter (104) utilising the pressure gradient which is in effect, and which can be maintained through continued use of the vacuum pump. Once the coffee has been collected in the collection vessel (102), the pressure in the apparatus and particularly the collection vessel can be brought up to atmospheric pressure utilising (117), and the collection vessel removed.

As shown in figure 2, in a preferred embodiment, evacuation means (108) and filtrate evacuation means (110) are connected through a tap (117) such that they can be pressure equalised and various parts of the apparatus evacuated simultaneously. Tap (117) also enables evacuation means (108) and filtrate evacuation means (110) to be evacuated independently, as may be required when the brewed coffee is to be vacuum separated. The apparatus of the invention may also further comprise one or more taps or valves to isolate the filter vessel from the coffee brewing vessel during the brewing process, and this can be facilitated for instance by including a tap or valve as part of cannula (106) (such as shown in figure 4).

Figure 3, shows an alternative apparatus to figure 2, and which also enables coffee to be brewed in accordance with the present invention and subsequently vacuum separated. The apparatus also comprises as its the main components: one or more vacuum pump for reducing the pressure in the apparatus to the range of 3.4 - 84.7 kPa (1-25 inHg); a coffee brewing vessel (105); a cannula (106); a steam condensing means (107) having an evacuation means (108); a filter vessel (100) having a filter (104) and at least one filtrate outlet (109) for connection to a collection vessel (102); wherein the filtrate outlet further comprises a filtrate evacuation means (110); and wherein the coffee brewing vessel (105) and the cannula (106) are configured to enable an aqueous medium contained in the coffee brewing vessel to be transferred to the filter vessel (100) by means and of the cannula under the action of a pressure differential provided by one or more of the vacuum pumps. This apparatus is also operated much in the same way as described in figure 2, but it has the advantage of being simpler in construction and therefore being easier to manufacture, to clean and to disassemble. This apparatus can also be compatible with a wide range of suitable steam PCT/IB2015/055859 WO 2016/038479 17 condensing means (107), i.e. for a glass apparatus particularly useful steam condensing means include glass dewar condensers, vigreux columns or a Findenser. Filtrate outlet (109) could be provided by way of a glass vacuum adaptor, and gas inlet (116) preferably includes a suitable tap so as to be able to carefully control the rate at which air can be reintroduced into the apparatus.

In another embodiment, and when the filter (104) comprises a filter paper (and particularly a prewetted / prewashed filter paper, such as being placed upon a glass sinter, or a perforated disc built into the apparatus), it may be preferable for filter vessel outlet (118) to be connected to the vacuum tubing through the use of an additional connection means such as a piece of vacuum piping or tubing (not shown in figure 3); wherein the additional connection means should be connected to the vacuum tubing at a position located between the vacuum outlet (113) and tap (117). This additional connection means also should comprise a separate tap or valve in order to ensure that filter vessel (100) can also be isolated from the vacuum outlet (113) during the brewing and filtration steps of the process. In the situation for instance where filter (104) comprises a filter paper and filter vessel outlet (118) is plugged through the use of a stopper (such as shown in figure 4), a situation can arise whereby given the increased air resistance of the filter paper relative to a steel mesh; during evacuation of the apparatus (such as in preparation for the brewing step), air contained within the filter vessel (100) can undesirably be forced down through the cannula and bubbled out through the coffee grounds. Accordingly, this bubbling of air through the coffee grounds slurry is potentially undesirable as it may cause some oxidation and deterioration of the coffee. The tap/valve in the afore mentioned additional connection means from filter vessel outlet (118) to the vacuum tubing is preferably in an open position when the pressure in the vessel is to be pumped down in preparation of the brewing step, wherein upon achieving the desired pressure, or at the commencement of the brewing step, or just prior to the the vacuum separation step, the tap/valve contained in said additional connection means is then closed, and should remain closed during the remainder of the extraction and/or vacuum separation steps. Such an additional connection means and its associated tap thereby prevents air from being bubbled through the coffee grounds and represents a more optimal solution to the overall brewing process, particularly when using an apparatus such as presented in figure 3.

Figure 4 presents an alternative apparatus to that shown in figure 3, but which works along similar lines. As shown in figure 4, the apparatus of the invention may also further comprise one or more taps or valves (119) to isolate the filter vessel from the coffee brewing vessel during the brewing process, and to thereby reduce the overall time taken to evacuate the apparatus in preparation for the brewing step. (119) may also optionally include a separate outlet to which a funnel (103) may be connected, and which thereby facilitates the addition of warm water directly to the coffee brewing vessel only after the apparatus has been assembled. (119) when used in combination with tap (117) can also be used to introduce hot water directly into the filter vessel (preferably with simultaneous use of the vacuum pump) for collection in the collection vessel, so as to suitably warm the apparatus just prior to use (the collected water then being discarded). Once water has been added to the coffee brewing vessel, and just prior to evacuating the apparatus for brewing the coffee grounds contained in the coffee brewing vessel, (119) and (116) are put in the fully closed position, whilst (117) is positioned so as to evacuate only the portion of the apparatus comprising the coffee brewing vessel. After the coffee has been brewed at reflux, (117) is then moved initially to the fully open position so as to stop the reflux extraction, as well as to reduce the pressure in the collection vessel and filter vessel. After the pressure has equalised, (117) is then moved to allow the filter vessel and collection vessel to be selectively evacuated, and (119) should then be moved to the open position to allow PCT/IB2015/055859 WO 2016/038479 18 passage of the coffee extract from the coffee brewing vessel to the filter vessel via (106). At this point (116) should be opened so as to accomplish the vacuum separation of the coffee grounds, and collection of the brewed extract.

In another embodiment of the present invention, the collection vessel (102) may optionally be fitted with a pressure valve / gas inlet / tap in its lower portion (see (120) in figure 5). In this way, and at the end of the process, the apparatus can be brought back to atmospheric pressure whilst simultaneously bubbling a gas through the collected coffee extract, wherein said gas is preferably selected from air, an inert gas such as carbon dioxide, or gasses and volatiles collected from the vacuum pump during the brewing process. In this way the final beverage can also be provided with some degree of crema. The combined use of such a pressure valve / tap with gas inlet (116) also makes it possible to remove the extracted coffee from the collection vessel (102) and straight into a cup or other external collection vessel.

For cleaning, waste coffee grounds can easily be removed from filter vessel (100) by means of a filter vessel outlet (118). In particular, if cleaning water enters the upturned disassembled apparatus through filtrate outlet (109), it will have a strong tendency to wash out the coffee grounds through the top of the apparatus, including any filter paper if utilised. A bottle brush or other similar device may also be used to help maintain the apparatus in a good clean condition. It should also be emphasised that in many cases the disassembled apparatus can also be cleaned in an automated machine such as a dishwasher as and when required.

Figure 5 presents an alternative apparatus for making Caffe Depurato by the process of the present invention. This apparatus is operated much in the same way as described for the apparatus of figures 2-4 (and being most similar in operation to the tap and vacuum tubing layout presented in figure 3). Figure 5 also exemplifies a coffee brewing vessel which incorporates a separate stoppered opening (121) which facilitates the addition of the brewing ingredients without first needing to dismantle the apparatus (a feature which can also be incorporated into the designs presented in any of figures 2-4). Prior to evacuating the apparatus, the stopper (121) can be removed, and and ingredients added, with can optionally be facilitated through the use of a suitably sized addition funnel. Once ingredients have been added, the stopper can be replaced, and it again preferable to use PTFE sleeves to help prevent the joints from sticking, as well as to help provide a better vacuum seal. Figure 5 is also exemplified incorporated a steam condensing means in the form of a Dewar type condenser which may be filled externally with cold water (or ice water, or other coolant for extended brewing times). The apparatus of figure 5 may also incorporate an optional secondary vacuum separatory component (122) which is able to separate any of the coffee particulates that escape the coffee brewing vessel as they exit the top of cannula (106). Due to the efficiency by which grounds can be vacuum separated in the coffee brewing vessel (on account of the proximity of the cannula opening to the bottom of the coffee brewing vessel), the presence of a filter compartment or filtration vessel may be optional. In this example for instance an optional and removable filtration stopper (123) and filter element (122) may be present, and as these components are easily removed, this also facilitates cleaning of the whole apparatus. Filter element (122) may comprise a plastic material such as high density polyethylene (HDPE), polypropylene, polyether ether ketone (PEEK), polyester, or PTFE, and may further comprise a small ring or section made from a fine mesh of a material such as stainless steel or a suitable plastic such as polyester. The filter may for instance have a mesh ranging in size from between about 5 micrometers and about 400 micrometers (40 mesh), and preferably between about 70 micrometers (200 mesh) and about PCT/IB2015/055859 WO 2016/038479 19 180 micrometers (80 mesh), and most preferably from about 125 micrometers (120 mesh) to about 150 micrometers (100 mesh). The diameter of the filter (and also as used in the context of any of the apparatus as discussed or claimed herein) typically may range from 10-250 mm, preferably between 10-80 mm, and most preferably between 15 and 70 mm. The diameter of the filter is usually selected taking into account the size of the mesh; when using a very fine mesh and/or a filter paper, the diameter of the filter tends to be on the larger size range to maximise the surface area, and to thereby reduce the filtration time; when using a courser mesh, the diameter of the filter can be smaller. In the case of the apparatus presented in figure 5 for example, if a mesh of around 180 micrometers is selected, then it would be appropriate to have a filter diameter of around 20 mm. As shown in figure 5, the main body of the filter element (122) may be shaped such that it can be placed in sandwich fashion, so as to form a seal between the collection vessel and the filtration stopper. As shown in figure 5, the collection vessel (102) preferably also comprises one or more fluid removal means (124), and which also preferably incorporates a valve or tap (120) to controllably facilitate the removal of the coffee extract. (120) should also be of a type which is able to withstand the reduced operating pressure of the apparatus, and must be able to remain closed during the brewing step.

Figure 6 shows a cross-section through the main part of the apparatus presented in figure 5, with the valve or tap (120) being shown in the closed position. The dashed line shown here represents the main portion of the filter element (122). The filter of (122) itself may be presented as a flat disk or else, it may be cone shaped (as shown in accordance with figure 6). From figure 6, it is also more easy to understand the working of the apparatus; at the end of the brewing step, and as the pressure in the lower coffee brewing vessel is increased towards atmospheric pressure, the aqueous medium / coffee slurry in the coffee brewing vessel, is drawn through the very narrow gap at the bottom of the cannula, to vacuum separate the vast majority of the coffee grounds (all sizes of grounds). After being drawn up through the central cannula, the aqueous coffee extract then passes through the filter element under the action of gravity, and also under action of the pressure differential, thus providing a second vacuum separation stage which is more suited to removing the minority of the finer particulates that pass through the cannula. The resultant coffee extract then collects in the collection vessel (102), and can be served as soon as the apparatus reaches atmospheric pressure.

It should also be emphasised that in accordance with the apparatus presented in figures 2-6, it is most preferable that the distance between the bottom of the cannula (106) and the lowest inside surface of the coffee brewing vessel (105) is about 1500 micrometres (microns) or less, such as between 10 and 1000 microns (e.g. about 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950 or 1000 micrometres), and preferably 500 micrometres (microns) ±300 micrometres. In this situation the majority of the coffee grinds are able to be kept efficiently in the coffee brewing vessel during the vacuum separation step, and this also increases the overall efficiency of the vacuum separation process, whilst also minimising the amount of liquid that remains in the coffee brewing vessel at the end of the whole process.

It should also be noted that the collection vessel (102) in any embodiment of the present invention may also be provided with a heating means so as to prevent the coffee extract from cooling to ambient temperature. The apparatus, and particularly the filter vessel (100) and/or the collection vessel (102) may also be rinsed with hot water and/or pretreated with steam prior to use to also help warm the apparatus. PCT/IB2015/055859 WO 2016/038479 20

The brewing apparatus of the invention, such as that as shown in figures 2-6 has the advantage of being able to reduce the overall time required to brew and separate the coffee grounds (relative to performing separate brewing and filtering steps in separate pieces of apparatus), as well as for providing an apparatus which is able to simply and cleanly separate the coffee grounds, whilst also reducing the likelihood of any accidental spillage or waste of the resultant coffee product. The inventive apparatus also enables the coffee grounds to be separated from the hot freshly brewed coffee whilst it is all still under reduced pressure and it can also utilise the same residual pressure after the brewing step to efficiently transfer the coffee to the collection vessel and to facilitate the vacuum separation of the coffee extract slurry. Indeed in many cases the vacuum separation step can be performed very rapidly and without any additional use of the vacuum pump. It is also preferable to separate the coffee grounds prior to exposing the coffee extract to atmospheric pressure, as this helps to ensure that some of the less soluble and less desirable coffee constituents are not solubilised into the extracted liquid as the pressure is increased. Accordingly, in another aspect of the present invention; after step c) but prior to and/or during step d) the extracted coffee grounds are separated from the extracted aqueous medium.

In accordance with the apparatus of any of figures 1-6, it should also be emphasised that a range of sizes of apparatus may be utilised. The coffee brewing vessel may for instance have an internal volume ranging from 100ml up to 20 litres or even more. Typically the collection vessel (102) may be chosen in size to be from 50-120% the size of the coffee brewing vessel. The size of the coffee brewing vessel in particular being chosen so as to contain 10-65% by volume of coffee slurry prior to, and/or during the brewing step. It being emphasised in this context that the coffee brewing vessel typically needs a minimum of 30% free head space so as to controllably facilitate the rapid loss of carbon dioxide during the brewing step. In the preparation of other beverages such as caffe mocha, the combination of carbon dioxide release, reflux conditions and additive components may result in a significant amount of foam formation during the initial 30 seconds of the brewing step, therefore at least 50% free head space is therefore generally preferred so as to enable this to be overcome and kept under control. Additionally the coffee brewing vessel may also comprise one or more inlets and/or one or more outlets which facilitate for the addition and removal of ingredients from the coffee brewing vessel, and without the need for complete disassembly of the apparatus. The collection vessel itself may also comprise one or more inlets or outlets for facilitating the removal of the coffee extract, and/or for modifying the pressure or atmosphere therein. One or more holding clips may also be utilised so as to ensure that the collection vessel does not fall away from the apparatus, particularly when the apparatus is brought back to atmospheric pressure.

In a similar way to when preparing a traditional coffee such as Greek coffee or Turkish coffee, the separation of the coffee grounds may be omitted completely. However, for most western tastes it is more usual to include one or more steps for separating the coffee grounds once they have been extracted. If one or more filtration steps are to be included, a range of types of filter and combinations thereof may be utilised. Although any suitable filtration media may be used, it is generally preferred to use either a mesh made of either plastic, glass or a suitable metal alloy as discussed herein. Alternatively, and in other embodiments a filter paper may also be utilised. Consideration must however be given to the type of filter as some types of metals can impact upon the flavour of the beverage, and impart an undesirable metallic flavour; in other cases a filter paper can also impart undesirable flavours and/or trap some of the flavoursome elements from the coffee extract, and it may often be desirable to prewash and/or rinse any filter paper before use. In view of these points, in some embodiments of the invention, the apparatus is designed such that the PCT/IB2015/055859 WO 2016/038479 21 coffee does not come into contact with any metal objects or metal parts during the performance of the entire method. In other embodiments, a filter paper is not used during any part of the process. In other embodiments, coffee grounds can be separated simply by forcing the coffee extract through one or more narrow slits or openings such as 1500 micrometres (microns) or less, such as between 10 and 1000 microns (e.g. about 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950 or 1000 micrometres), and preferably 500 micrometres (microns) ±300 micrometres. When performing the method in an apparatus comprising a cannula (such as presented in figures 2-6), a specific filtration step may be optional, or at least partially redundant, and/or is preferably optimised to trap finer particulates such as having average particle diameters of 400 micrometres (microns) or less; this is because when using such an apparatus, the invention can take advantage of the very small spacing between the bottom of the cannula and the inside of the coffee brewing vessel to perform the major part of the vacuum separation step; wherein said spacing may be of 1500 micrometres (microns) or less, such as between 10 and 1000 microns (e.g. about 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950 or 1000 micrometres), and preferably 500 micrometres (microns) ±300 micrometres. In such an apparatus, and when the pressure in the coffee brewing vessel is increased at the end of the brewing step, the lower part of the cannula, and the bottom of the coffee brewing vessel will typically engage with some of the larger particulate coffee grounds, and can thereby advantageously and efficiently vacuum separate in excess of 98% by weight of all of the grounds within the coffee brewing vessel, including those particulates which are substantially smaller than the spacing between the lower part of the cannula, and the bottom of the coffee brewing vessel. Such a separation process can also be performed without any significant obstruction to the flow of the extracted aqueous medium exiting the coffee brewing vessel. In particular the apparatus presented in figure 5 fully exploits this phenomenon in that it provides a separate removable filter element (122) which is designed to capture only the small amount of coffee particulates that exit the top of the cannula.

Notwithstanding the coffee grounds separation methods discussed above, coffee brewed in accordance with the present invention may also be separated, and/or filtered independently such as through the use of an external filtration device, such as through the use of a standard cafetiere pot (and which may be plunged immediately upon pouring the coffee from the coffee brewing vessel (105)). Freshly brewed coffee obtained in accordance with the process of the present invention can also be filtered externally using any type of commercial coffee filter paper, and which may be performed using gravity at atmospheric pressure, or else under an applied vacuum. In other embodiments, the roasted coffee grounds may be prepackaged and encapsulated within a porous membrane, such as a filter bag, and which can be subsequently introduced in the coffee brewing vessel, with the coffee brewed without the need for any additional separation process, or separation device. Alternatively, freshly brewed coffee obtained in accordance with the process of the present invention can also have the coffee grounds separated under the application of external pressure such as used by the Aeropress® method, or as used in the preparation of espresso, and/or the Nespresso® system. A step of separating the coffee grounds, and which follows the inventive brewing process of the present invention is therefore in no way limited only to the application of vacuum separation methods. Many vacuum pumps are also capable of applying a positive pressure; and whilst it is possible to utilise the same pump to accomplish the reduced pressure brewing step as well any subsequent positive pressure filtration step, it may be more preferable to use separate pumps which are each dedicated to a fulfilling a particular part of the overall process. PCT/IB2015/055859 WO 2016/038479 22

Once the brewing step of the invention has been completed (and after any optional grounds separation process has been completed), it may be preferable to reheat the extracted coffee by reducing the pressure down to about 33.9 kPa (about 10 inHg), and to heat the extracted coffee product until it starts to boil (this process being facilitated by the apparatus in figure 1 which can be fitted with a vacuum pump at the top). This ensures the brewed / extracted coffee product is at an optimum serving temperature and cannot be over heated. The pressure can then be increased to atmospheric pressure and the coffee served immediately.

In a similar way to the Nespresso® system, it would also be possible to produce / obtain a prepackaged product, such as in the form of a capsule, and which comprises substantially anhydrous ground roasted coffee beans (i.e. which contain less than 4% by weight water, more preferably less than 1% by weight water, and most preferably less than 0.1% by weight water), and which is ideally packaged under an inert atmosphere. In a suitably designed apparatus, the upper portion of the capsule may be pierced with a suitable piercing means, and warm water injected at positive pressure. The injection pressure would typically be lower than used in a conventional Nespresso® system, so as not to rupture the lower frangible seal of the capsule. The walls of the capsule may then form at least part of the coffee brewing vessel, such that the pressure within the capsule is able to be pumped down into the range of 3.4 - 84.7 kPa (1-25 inHg). A heat source may then be applied to the exterior portion of the capsule, and/or via the capsule piercing means such that the contents of the capsule may be brought to reflux whilst maintaining the pressure within the range of 3.4 - 84.7 kPa (1-25 inHg). After the brewing stage is complete, the pressure in the capsule is increased to at least atmospheric pressure. Furthermore if sufficient pressure could be provided, the frangible seal may then be broken thus enabling the extracted coffee to be released and the grounds separated. Such a process thereby maintains much of the convenience and simplicity associated with the Nespresso® system, but due to the lower extraction temperature in combination with the advantages provided by the reduced pressure extraction technique of the present invention and as discussed herein; the present process is better able to provide coffee beverages with an improved flavour profile and less bitterness.

In another embodiment of the present invention, the extracted coffee may also be subjected to further processing steps such as freeze-drying, spray-drying / lyophilisation etc. in order to produce an instant coffee product. Suitable steps being generally known in the art, many of which being described for instance in WO2013/019676 (the contents of WO2013/019676 being incorporated herein by reference in its entirety). Such a dried product may also be further blended with coffee aroma extracts, and/or unextracted fresh coffee grounds as is well known in the art.

The apparatus for performing the present invention may be made out of any suitable material, but particularly preferred materials for the main parts of the apparatus are preferably made of glass, stainless steel, or titanium alloys such as Ti-6AI-7Nb, or ATI 425® Alloy. Other preferred materials such as polypropylene (PP) or polyether ether ketone (PEEK) may also be used. Other suitable materials including metals such as aluminium, copper, zinc, iron and alloys thereof, plastics (including materials such as HDPE, PVC, etc.), and so on, are also within the scope of the present invention.

Preferably, and in accordance with the present invention, the pressure during the brewing process should be between 3.4 and 84.7 kPa (1-25 inHg), such as at 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24 and 25 inHg ±0.5 inHg. Preferably the pressure during the brewing process should be between 13.5 kPa and 67.7 kPa (i.e. between 4 and 20 inHg), more preferably between 23.7 kPa and PCT/IB2015/055859 WO 2016/038479 23 50.8 kPa (i.e. between 7 and 15 inHg), and most preferably at about 33.8 kPa (i.e. 10 ± 2 inHg / between 27.0 and 40.6 kPa). The coffee grinds and the aqueous medium are usually placed in the coffee brewing vessel at atmospheric pressure prior to reducing the pressure in the coffee brewing vessel. However, such as in the context of an automated apparatus, the pressure in the coffee brewing vessel may first be reduced into the range of 3.4 and 84.7 kPa (1-25 inHg), and then the coffee and/or the aqueous medium can then be introduced whilst the reduced pressure atmosphere is maintained. The bitterness of the refluxed coffee beverage is somewhat dependent upon the pressure that is prevalent during the reflux brewing step; as the pressure during the reflux brewing step is increased, so does the bitterness of the resultant beverage. Whilst the bitterness of the beverage can be reduced to some extent by reducing the brewing time, at pressures above 67 kPa (about 20 inHg) this starts to become more difficult and the difference in taste between a conventionally prepared coffee (e.g. prepared in a conventional manner using a French Press and as discussed previously) becomes harder to distinguish. Conversely if the brewing step is performed under too low a pressure, excess energy is essentially wasted to evacuate the coffee brewing vessel; below about 13.5 kPa (about 4 inHg) there is no further noticeable improvement in coffee flavour, and the coffee brewing time also has to be increased to achieve a comparable degree of extraction. A hand vacuum pump also cannot be utilised to achieve pressures below about 13.5 kPa (4 inHg), and this therefore also requires the use of a specialised electrical vacuum pump. More importantly however, at pressures below 10 kPa (3 inHg) and especially below 6.8 kPa (2 inHg), it becomes increasingly difficult to condense the resultant steam that is obtained during the brewing step. Typically below about 6.8 kPa (2 inHg), it also becomes impractical to utilise either water or air to condense the resultant steam. Accordingly and in order to safeguard the longevity of the vacuum pump, at pressures below about 10 kPa (3 inHg), a cold trap becomes absolutely necessary, and this requires the use of a more expensive coolant such as solid carbon dioxide or liquid nitrogen. The use of a cold trap also has the further disadvantage as it prevents condensed steam in the form of ice from being returnable to the coffee brewing vessel. Accordingly, at pressures below about 6.8 kPa (2 inHg), the liquid in the coffee brewing vessel cannot be maintained under a state of reflux, as the boiling liquid is rapidly lost from the coffee brewing vessel which becomes essentially impossible to prevent, with no advantage being provided to the resultant beverage.

The atmosphere within the coffee brewing vessel whilst it is under reduced pressure is typically air, however in other embodiments of the present invention, the brewing step is performed in an atmosphere which is substantially free of oxygen (i.e. wherein the atmosphere in the coffee brewing vessel contains less than 2% by weight oxygen, more preferably less than 0.1% by weight oxygen, and most preferably less than 0.01% by weight oxygen). An atmosphere which is substantially free of oxygen can be achieved for instance by flushing through with any inert gas or a mixture thereof, or by a method comprising the repeated evacuation and charging of the apparatus and coffee brewing vessel with the inert gas. Preferably such gases are selected from the group consisting of nitrogen, carbon dioxide, argon and mixtures thereof. Whilst nitrogen is typically the most economically viable, carbon dioxide and argon have the advantage in that they form a blanket over the brewing coffee due to them being heavier than air. Argon in particular is the most effective at minimising the exposure of coffee in the coffee brewing vessel to oxygen, even when the pressure ranges from 3.4 - 84.7 kPa (1-25 inHg). In most instances however it is generally not required to perform the brewing step under a protective atmosphere, this is because a significant amount of carbon dioxide has been found to be released during the brewing process, and this being heavier than air typically forms a blanket over the brewing coffee thereby reducing the likelihood of excessive oxidation reactions occurring during the brewing step. WO 2016/038479 PCMB2015/055859 24

The present invention is able to be performed with a wide range of different coffee roasts and coffee grinds. The coffee grounds can be of a range of particle sizes, since the brewing step of the present invention is generally more effective for extracting flavours from deeper within the coffee grinds than with conventional coffee extraction techniques known from the existing prior art. The particle size of the coffee grounds used in a single brewing step of the present invention can therefore include quite a wide distribution of particle sizes. Utilising the present invention, an espressos style coffee can for instance be obtained utilising coffee grounds which are obtained using a relatively course ground setting. A coffee extract can therefore be obtained using coffee grounds which have a diverse particle size distribution, such as having some particles with diameters of up to 3 mm, as well as including many particles having sizes of less than 500 micrometres (microns) or even less than 100 micrometres (microns). Generally however it is still nonetheless preferable to utilise coffee grounds having a narrow particle size distribution, as this helps to ensure that the beverages are generally more consistent in flavour. Furthermore, since smaller particles have an increased surface area it is also often preferable to utilise coffee which is of a very fine grind. However, since coffee which is of a very fine grind quickly deteriorates, it must either be used when freshly ground, or else it should only be used when stored and/or packaged correctly. Another aspect which affects the choice of the coffee grind size is the method chosen for separating and removing the coffee grounds (which in some instances may be omitted altogether), and also taking into account the particle size associated with any optional additives. The smaller the average particle size, the longer the separation step typically takes. For brewing coffee in the absence of any additives, it may often be preferable to use a medium-fine grind in conjunction with a very fine mesh or filter paper. When brewing coffee with additives such as finely ground/powdered cinnamon for instance, it may be preferable to utilise a slightly courser grind of coffee, and to filter utilising either an appropriate grade of filter paper, or else a relatively fine mesh. This can then achieve a more reasonable duration for the separation step, as the coarse coffee grounds themselves act as a filter in that they prevent many of the smaller particulates from reaching and clogging the filter. For brewing a caffe mocha utilising cocoa powder with a small particle size, it may be preferable for instance to utilise coffee of a medium fine grind size (such as in the range of from 100-800 micrometres (microns)). The optional separation step can then for instance be conducted utilising a stainless steel mesh with a high surface area and large filter diameter. This then enables the majority of the coffee grounds to be separated whilst still allowing most of the cocoa particulates to find their way into the beverage. For these reasons, and as used herein, the term "coffee grounds” should be seen to include all coffee grind sizes and particle size distributions as can be obtained by a person skilled in the art, utilising all such applicable grinding methods as known in the wider art. In accordance with the present invention, the coffee grounds to be utilised can therefore have an average particles size ranging from around 3000 micrometres (microns) down to around 700nm, and independently in both wide and narrow particle size distributions. In a preferred embodiment all of the particles should be less than 3000 micrometres (microns) in diameter, and more preferably less than 1000 micrometres (microns). Most preferably the average particles size ranges from 10 to 400 micrometres (microns). Suitable coffee grounds may be obtained by conventional coffee grinding apparatus, as well as by other highly specialised techniques and apparatus, this includes without limitation, dry grinding/milling techniques, wet-milling techniques and also a range of nano-milling techniques as used in the pharmaceutical industry.

During the brewing step, it is preferable to maintaining the temperature of the water in the coffee brewing vessel to be between the water reflux temperature and 10°C below the water reflux temperature. It is more PCT/IB2015/055859 WO 2016/038479 25 preferable to maintain the temperature of the water in the coffee brewing vessel to be between the water reflux temperature and 2°C below the water reflux temperature. It is most preferred to ensure that sufficient heat is provided via the heater (125), and under a stable vacuum so as to continuously and vigorously reflux the coffee in the coffee brewing vessel during the brewing step. It being particularly preferred to ensure that during the brewing step; the fluid in the coffee brewing vessel has a characteristic appearance of a boiling foam, with the foam layer initially being at least 0.5 cm in depth, and which is prevalent across the whole upper surface of the boiling liquid. At 33.9 kPa (10 inHg) for instance the reflux temperature typically being around 70°C. Any suitable heat source may be utilised, and this includes without limitation: electrical conduction heaters (including the use of heating mantles, hot plates, stovetops utilising oil or water baths), induction heaters, microwaves, immersion heaters, open flames, or light irradiation such as by using one or more halogen lamps. It is also most preferable for the heater to incorporate one or more thermostats (126), which can be located within the heating unit itself or else incorporated into other parts of the apparatus so as to ensure that the coffee brewing vessel itself is not overheated.

During the brewing step it is preferable to brew the coffee from between 10 seconds and 30 minutes. It it more preferable to brew the coffee from between 30 seconds and 10 minutes, and more preferable to brew the coffee for between 1 and 5 minutes, and most preferable to brew the coffee for 2 minutes ± 30 seconds. As the brewing time is increased the bitterness of the beverage gradually increases. For a brew of freshly ground medium roasted arabica coffee, a brew for 10 minutes at continuous reflux at 50.8 kPa (15 inHg) produces a coffee very rich in flavour, with a long sustained flavour, but also with a distinct but not unpleasant bitterness. The noticeable bitterness obtained under such more extreme conditions was still not found to be excessive, and the extract was still very drinkable, although perhaps not to everyone’s taste. In contrast, if the brew time is too short, or the brew temperature is too low, the coffee does not attain its true potential richness of flavour. It is however generally preferable to continue brewing the coffee until there is no further significant release of carbon dioxide from the coffee grounds and brewing medium. For most coffee grounds the release of carbon dioxide is largely completed within the first ninety seconds of achieving reflux. A brew time of 2 minutes continuous reflux at 33.9 kPa (10 inHg) was therefore found to be preferable for a large range of coffees, grind sizes, and coffee:water (aqueous medium) ratios (weight:weight ratio).

It is preferable to calculate the brewing time from the point at which the water reflux temperature has been reached as discussed above. The end point of the brewing step could be determine either from the time taken from first arriving at the water reflux temperature, or else it could be determined using a temperature probe positioned towards the upper portion of the steam condensing means. In an automated machine, such a probe could also be used to safeguard and protect the vacuum pump, as it can also be used to halt the brewing process once the upper portion of the steam condensing means reaches a critical shut-off temperature.

In accordance with the present invention, the coffee brewing vessel typically contains only coffee grounds and water. However, in another embodiment of the present invention, the coffee brewing vessel may also comprise one or more additives, and/or the water is provided in the form of a water containing medium. Suitable additives and/or sources of water include ingredients such as cocoa, fresh milk, milk powder, salt, sugars or other sweeteners (including refined maple syrup, honey (particularly manuka honey), sucrose, Steviol glycosides, Rebaudioside A, sucrose, saccharin, aspartame, sucralose etc.), flavours, PCT/IB2015/055859 WO 2016/038479 26 essential oils, vitamins, minerals, fruit juice(s) and/or fruit pieces (including juice, flesh or peel etc, derived from fruits such as oranges, lemons, quince, apples, pears, strawberries, vanilla, raspberries, mangoes, black currants, red currants, custard apples, longans, lychee, gooseberry, rambutan, pineapples, bananas, tomatoes, guava, passion fruit etc.), herbs and/or spices (including without limitation cinnamon, ginger, coriander, cumin, turmeric, chilli, Sichuan pepper, paprika, cardamom, black pepper, cloves, nutmeg, mustard, fennel, tarragon, fenugreek), preservatives, colourants etc.. Furthermore, given that coffee already includes several pharmaceutically active compounds, there is no reason why further pharmaceutically active ingredients cannot be included within the coffee brewing vessel prior to and during the extraction of the coffee grounds. The present invention therefore also provides coffee extracts that are obtained from the brewing process with the inclusion of fine particulate forms of pharmaceuticals, and/or dissolvable forms of pharmaceuticals intended for the treatment of pain, inflammation, viral infection, bacterial infection, obesity, pain, depression, diabetes, cancer, tumour, multiple sclerosis, heart disease, etc. etc., and thereby encompassing the inclusion of representative pharmaceuticals such as, and without limitation; aspirin, paracetamol, ibuprofen, tramadol, diclofenac, codeine, morphine, testosterone, prednisolone, cannabidiol (and also its many structural analogues), penicillin and its derivatives etc. and the mixtures thereof. In an automated machine for instance, a prepackaged product comprising ground coffee and one or more additives could for instance be provided in the coffee brewing vessel, water could then be added during step a) of the brewing method. Alternatively, beverages can equally be obtained in accordance with the present invention by brewing a mixture comprising ground coffee and an aqueous medium such as high quality orange juice.

In accordance with the present invention, a variety of vacuum pumps (127) are suitable. Whilst the vacuum pump can be automated, it is also possible to use a relatively inexpensive hand vacuum pump such as a Mityvac MV8000 or more preferably a Lisle 75000 Vacuum Pump both of which have been found to be ideally suited to use in accordance with the present invention. A number of relatively inexpensive 9-24V DC vacuum pumps are also available on the market which are also capable of reaching the preferred pressure range. A small (e.g. 10 x 7 cm) and highly portable DC vacuum pump operating at 15V (such as running on 10 NiMH AA batteries) for instance was found to be ideally suited for evacuating the apparatus down to a pressure of 25.4 kPa (7.5 inHg), even over several months of continued daily use and without the need to recharge the batteries. Furthermore, and utilising the various pressure valves incorporated into the brewing apparatus, the pressure within the coffee brewing vessel could for instance be adjusted to be anywhere from 25.4-100 kPa (7.5-30 inHg). The use of larger mains operated rotary vane vacuum pumps or diaphragm vacuum pumps is also anticipated. Many electrically operated vacuum pumps are however relatively noisy, and it is therefore preferable to choose a model that operates, and/or can be modified to operate at a lower noise threshold. Regardless of what vacuum pump is chosen, it is most preferable for the brewing apparatus to be fitted with a vacuum gauge (128) so that the pressure can accurately be measured and controlled. The apparatus should also be provided with a means of reintroducing air back into the system, so as to be able to control the pressure as well as to be able to equilibrate parts of the apparatus back to atmospheric pressure at the end of the extraction process. This can be achieved either using a separate pressure valve (116), or in other embodiments of the invention a vacuum pump may be chosen which incorporates its own vacuum release valve (116).

In accordance with the present invention, the coffee:aqueous medium ratio (based on a weight basis) is an important factor that affects the strength of the resultant coffee, and is customised according to the type PCT/IB2015/055859 WO 2016/038479 27 and style of beverage that is desired. In accordance with the present invention, the coffee:water ratio has minimal impact upon the bitterness of the beverage, it really only has an effect on the intensity of flavour and/or the strength of the beverage that is produced. The present invention is therefore particularly suited for brewing stronger types of coffee such as espresso style coffee (Caffe Espresso Depurato) but without the usual bitterness which is often associated with typical Caffe Espresso. For a beverage much akin to a traditional filter coffee in strength, but with added depth and flavour, it is usual to use around 5-8g of coffee per person for every 200-250 g of water (i.e. to provide a coffee:water ratio in the region of 1:25-1:50). For an espresso style beverage it is recommended to use about 10-18g of espresso coffee per person for about 50-100 g of water (i.e. to provide a coffee:water ratio in the region of 1:2.78-1:10).

In accordance with the present invention, the resultant coffee extract can also be subjected to further processes. In accordance with known methods, an extract obtained in accordance with the present invention can for instance be subject to drying in order to produce a coffee concentrate and/or substantially anhydrous product (i.e. which contain less than 4% by weight water, more preferably less than 1% by weight water, and most preferably less than 0.1% by weight water). The resultant dried product is shelf-stable and can form the basis of an instant-coffee product, or else it can be used in food products to impart a distinctive coffee flavour. A packaged article comprising a blend of the afore mentioned dried coffee product in combination with ground roasted coffee beans is also anticipated by the disclosure of the present invention.

Examples

Example 1

To make a cup of coffee of a similar strength to a traditional cup of filter coffee, 7g of freshly ground coffee beans (medium-fine grind) were placed in a 500 ml round bottom flask fitted with a B24 ground glass joint, and equipped with a heating mantle. To this was added 230g of prewarmed good quality filtered water. A dewar condenser fitted with a Teflon® joint sleeve (i.e. manufactured from polytetrafluoroethylene / PTFE) was then placed on top, and the dewar condenser filled with cold water to provide a cold internal surface for steam to condense upon. A Mityvac MV8000 vacuum pump was then fitted to the outlet on the top of the condenser through another ground glass joint and Teflon® sleeve, and the pressure was reduced to an actual pressure of 33.9 kPa (10 inHg) (thereby reading 20 inHg on the reversed gauge). Heat was applied by way of the heating mantle, and the coffee was brought up to reflux. Once an even boil was established, the coffee was brewed at a continuous vigourous reflux for two minutes, whilst maintaining the pressure at around 33.9 kPa (10 inHg). After the brewing period, the heat was removed, and air was allowed back into the system via the vacuum pump. The condenser was removed, and the coffee, vacuum separated in a suitable apparatus such as that presented in figure 1. The contents of the collection vessel (102) were then be poured into a suitable mug and the coffee was ready to be drunk or milk and/or sugar to be added. This example has been repeated numerous times with a range of different types of fresh coffee and a variety of different grinds, the resultant coffee is always consistent in being of a fuller flavour and being exceptionally smooth and mellow. Blind tests have also been conducted numerous times, and the difference between coffee brewed in accordance with the above example and a comparative Cafetiere of the same coffee and coffee:water ratio is always immediately apparent, with the coffee brewed in accordance with the exemplified process being preferred in almost every instance. PCT/IB2015/055859 WO 2016/038479 28

Unlike coffee produced by other methods; prior to any optional grounds separation steps, the coffee brewed in accordance with the present invention typically has absolutely no foam or bubbles floating on the surface, and there is generally no coffee particulate residue floating at or near the upper surface of the liquid. This demonstrates that the customary brown foam or crema (such as observed when placing coffee grounds in direct contact with hot water) is eliminated during the brewing process, and the coffee grounds are more fully extracted with any air pockets within the grounds also being effectively removed.

Example 2

To make a Caffe Latte Depurato, 15g of preground Lavazza espresso coffee was placed in a 500 ml round bottom flask with 95g of cold water. The method of example 1 was then repeated again by brewing the coffee under a vigourous reflux for two minutes at 33.9 kPa (10 inHg). The resultant coffee was filtered and was poured from the collection vessel (102) into a coffee mug containing 2/3 of a cup of prefoamed and warmed milk.

Independent tests with a control sample produced on a commercial espresso machine have been very well received, especially since the results obtained using the present invention are always reproducible, and the cost of the apparatus required to perform the present invention can be significantly smaller.

Example 3

To simultaneously make four cups of espresso style coffee (i.e. Caffe Espresso Depurato), 60g of freshly ground (medium-fine grind) coffee was placed in a 1 litre round bottom flask with about 380 ml of good quality warm water (typically between 50 and 65°C). After fitting the dewar condenser, the pressure was reduced to 33.9 kPa (10 inHg) and heat was applied by means of an external water bath using a standard kitchen stove on medium heat. Once the contents of the flask start to boil the heat on the stove was turned down to minimum, and the coffee continued to reflux at 33.9 kPa (10 inHg) for 2 minutes. After the brewing period, the water bath was removed, and the pressure brought back to atmospheric pressure. After removing the condenser, the coffee was vacuum separated in a pre-warmed apparatus comprising a receiving vessel (such as being of a type similar to those used on a cona coffee maker / vacuum pot, or a coffee cone fitted with a suitable filter paper), the receiving vessel being fitted onto a collection vessel which has a receiving inlet, and a pouring / vacuum outlet. The brewed coffee and coffee grounds being vacuum separated by pouring the coffee slurry into the receiving vessel with an operating vacuum pump being connected to the vacuum outlet. Under these conditions, the coffee quickly filtered through the filter and collected in the collection vessel (the collection vessel may also be equipped with a heat source so as to keep the coffee warm during this process). The vacuum separatory apparatus presented in figure 1 may also be used in preference. The resultant coffee was then poured out into four large warm espresso cups and served.

Example 4

To prepare 1.8 L of coffee comparable to a traditional filter strength coffee, 70g of finely ground coffee was placed in a 1 litre round bottom flask fitted with a B24 ground glass joint. 700ml of warm water were then added. A dewar condenser was then fitted along with a vacuum pump. The pressure was then reduced to 40.6 kPa (12 inHg) and the coffee brought to the boil. The coffee was then brewed at reflux PCT/IB2015/055859 WO 2016/038479 29 for two minutes. The resultant coffee was then vacuum separated through a filter paper, and the filtrate brought back to the boil at a pressure of 33.9 (10 inHg). As soon as the coffee started to boil, the pressure was increased to atmospheric pressure and the coffee poured out into a large thermos flask. To the coffee with stirring was then added 1.1 litres of 75°C warm water. The coffee was then ready for consumption, and was found to be much more mellow and refined than a comparable filter coffee made using the same ground coffee, same final coffee:water ratio and the same type of filter paper.

Example 5

To make an extra rich cup of coffee with long lasting tones and a not unpleasant bitterness, 7g of freshly ground (medium-fine) coffee was placed in a 500 ml round bottom flask fitted with a B24 ground glass joint, and equipped with a heating mantle. To this was added 230g of prewarmed good quality filtered water. An air condenser was then placed on top (fitted with a Teflon® sleeve at each end). After connecting the vacuum pump the pressure was brought down to 50.8 kPa (15 inHg), and the water brought to reflux. After 10 minutes at continuous vigourous reflux, the pressure was increased to atmospheric pressure. The hot filtered coffee was then placed in a large mug, with a little foamed warmed milk added. Although having notable bitter tones, the coffee still had a smoothness and was nonetheless enjoyable and found to be unlike any other coffee ever tasted.

Example 6 (Comparative)

In order to gain a further understand of the brewing process of the present invention, 7g of roasted, whole unground coffee beans was placed in a 500 ml round bottom flask fitted with a B24 ground glass joint, and equipped with a heating mantle. To this was added 230g of prewarmed good quality filtered water. A dewar condenser filled with cold water was then placed on top, and fitted with a Teflon® sleeve at each end. After connecting the vacuum pump the pressure was brought down to 33.9 (10 inHg), and the water brought to reflux. After 10 minutes at continuous vigourous reflux (some ice was added to the condenser to ensure its effective cooling), the pressure was increase to atmospheric pressure. The resultant coffee solution had turned lemon yellow in colour, and had a distinct coffee taste and aroma but was not as strong as the preceding examples, thus showing that a significant extract was obtained even using whole coffee beans. The coffee beans themselves had softened considerably and could easily be squashed and broken apart by hand. This demonstrates that the method of the present invention significantly increases the porosity of the coffee grinds, and provides for a much better and more even extraction of the grinds (this is further demonstrated by the ATR-FTIR analysis as described later in example 12).

Example 7 Brewing method utilising the apparatus presented in figure 2. 7g of freshly ground (medium-fine) coffee was placed in coffee brewing vessel in the form of a glass 500 ml flask fitted with a ground glass joint. Approximately 230g of prewarmed filtered water was then added to the coffee brewing vessel. The coffee brewing vessel was then attached to a glass apparatus manufactured to be substantially in accordance with figure 2, which also included a collection vessel in the form of another clean glass 500 ml flask, and fitted with a glass stopper at filter vessel outlet (118). Cold water was then incorporated into the cold finger of the apparatus through the coolant inlet which was fitted with a removable funnel to facilitate the water addition. The coffee brewing vessel was then placed in PCT/IB2015/055859 WO 2016/038479 30 conjunction with a heating mantle. Tap (117) was initially ensured to be fully open, whilst gas inlet (116) was closed. A vacuum pump was then connected via outlet (113). The apparatus was then pumped down to a pressure of 33.9 kPa (10 inHg), and the coffee brewing vessel heated to reflux, whilst still maintaining the pressure at about 33.9 kPa (10 inHg ± 2 inHg). After two minutes of continuous brewing at reflux, the pressure in the vessel was increased slightly by partially opening the tap of gas inlet (116) so as to stop the coffee mixture from boiling. Tap (117) was then turned so that the filtrate outlet (109) could be evacuated without first reducing the pressure in the condenser. Gas inlet (116) was then gradually opened whilst still maintaining a partial vacuum in the filter vessel (100). The hot coffee and coffee grounds were consequently controllably sucked into the filter vessel and the coffee passed through the filter and into the collection vessel. Upon completion of the filtration step, tap (117) was then reopened so as to equilibrate the pressure to atmospheric pressure, the collection vessel was then removed and the Caffe Depurato served.

Example 8

To make a Cinnamon Latte Depurato, 15g of freshly ground roasted coffee was placed in a coffee brewing vessel with quarter of a teaspoon of ground cinnamon powder. Warm water (95g) was then added, and the cinnamon coffee mixture brewed at reflux at 33.9 kPa (10 inHg) for 2 minutes in accordance with Example 1. The brewed product was then vacuum separated through a fine coffee filter paper to remove all particulates, and the filtrate collected in a collection vessel. Separately, half a mug of foamed hot full fat milk was provided, and the filtrate added with stirring. The resultant beverage was then served, and had a distinctive cinnamon aroma, and a rich satisfying coffee and cinnamon taste.

Example 9

To make a coffee beverage containing a natural vanilla extract, 7g of fresh coffee was placed in a coffee brewing vessel with a small quantity of freshly ground vanilla pod. Approximately 130 ml of warm water was added to the coffee brewing vessel, and the mixture brewed at reflux at 33.9 kPa (10 inHg) for 2 minutes in accordance with Example 1. The brewed product was then vacuum separated through a coffee filter paper to remove all particulates, and the filtrate collected in a collection vessel. The resultant beverage was served (to which milk and sugar may subsequently added as desired). The brewed coffee had a distinctive vanilla aroma, and had a pleasant taste of fine quality coffee combined with a noticeable vanilla flavour.

Example 10

To make a caffe mocha, 14g of ground fresh roasted coffee beans (average particle size of approximately 1000 micrometres (microns) in diameter) were placed in a coffee brewing vessel along with 12g of coarsely chopped dark chocolate (ideally no greater than 5-10 mm in diameter), 3g of fine cocoa powder (sieving optional but certainly not required), 16g of brown sugar (i.e. partially refined household sugar, or alternatively a sweeteningly equivalent amount of a suitable artificial sweetener may be substituted) and a small quantity of salt. Warm water (100ml) was then added to the coffee brewing vessel, and the pressure in the coffee brewing vessel was pumped down to 33.9 kPa (10 inHg). The coffee brewing vessel was then brought to reflux without the need for stirring, and reflux was sustained at 33.9-37.3 kPa (10-11 inHg) for two minutes. The pressure in the coffee brewing vessel was then increased to atmospheric pressure. The contents of the coffee brewing vessel were then filtered utilising a stainless steel mesh under the application PCT/IB2015/055859 WO 2016/038479 31 of external pressure (the mesh size should preferably be chosen so as to filter the coffee particulates, but to allow the chocolate suspension to pass relatively unhindered) (a French press could be used as a viable substitute to replicate this filtration process). Warmed foamed milk was then added to the resultant filtrate in a cup and the beverage was served.

The beverage of this example had strong satisfying flavours of both coffee and chocolate, and had the advantage of being extremely simple to prepare. The method of the present invention also has the advantage that a separate chocolate syrup need not be prepared, and an extensive stirring step for the chocolate is also not required; the reduced pressure / reflux agitation is extremely effective at breaking down any large chocolate, cocoa and sugar particles to produce a smooth and essentially homogenous product. This example is also ideally suited for use in an automated process utilising a prepackaged essentially anhydrous product, where only water needs to be added prior to brewing the beverage in accordance with the invention.

Example 11 - liqueur coffee e.g. caffe rosso

The present invention is also suitable for preparing a range of liqueur coffees of which Irish coffee is just one such obvious example. For instance, and to make a unique and inventive beverage best described as a caffe rosso; 15g of good quality ground coffee per serve (e.g. illy espresso coffee) and optionally a small amount of sugar (such as lg or ^ teaspoon per serve) are placed in a suitably sized coffee brewing vessel with around lOOg per serve of Martini Rosso (15% alcohol by volume) as the aqueous medium (spirits such as Martini may be used neat, or more preferably may be mixed with water such as in a 50:50 ratio by volume). The coffee brewing vessel should be fitted with an efficient condensation means and placed under reduced pressure such as to around 33.9 kPa / 10 inHg, prior to heating the contents of the vessel to reflux. After continuous reflux at around 33.9 kPa / 10 inHg such as for up to around 2 minutes, the flask should be brought to atmospheric pressure, and the contents filtered to remove coffee grounds, and to thereby produce in this case a deep red coloured extract. For the caffe rosso, the filtrate is to be poured into ice and allowed a minute or so to cool before cold milk is added slowly and to prevent curdling. The ice is then preferably removed such as by passing through a coarse filter, before serving. Fresh cream my also be added in place of milk or a mixture therewith, wherein the volume of milk and/or cream is sufficient to give an attractive colouration, as well as to complement the flavour of the beverage. A small amount of whipped cream may also be placed on top of the beverage prior to serving.

Examples 8-11 demonstrate the easy by which additional flavours and additives can be introduced into a coffee beverage utilising the apparatus and methodology of the present invention. The present invention thereby provides a means by which a prepackaged coffee and flavourant / additive pack could be brewed in admixture to provide a beverage having an enhanced coffee flavour in combination with one or more additives which bring further satisfaction to the beverage. The use of such a prepackaged coffee / additive pack in a fully automated process analogous to a Nespresso® type system, but utilising the brewing method of the present invention is also very much within the scope of the invention and as defined in the claims. Alternatively, the process of the present invention could be performed in a specially modified vending machine, and which may be particularly attractive in the Japanese market.

Example 12 - ATR - FTIR Spectroscopy PCT/IB2015/055859 WO 2016/038479 32

As discussed herein above, coffee extracts contain a vast array of diverse chemical constituents which are present in varying quantities and have diverse chemical functional groups. Many of these chemical compounds are also unstable and/or are sensitive to light and/or oxygen. Coffee samples also include a range of particulate matter which also has varying implications for different types analytical techniques. The combination of these issues makes the analysis of coffee samples extremely challenging. Whilst techniques such as GCMS and LCMS for example are good methods for detecting the presence of specific compounds (they rely upon separating the individual compounds), they cannot however be used to measure parameters associated with all of the chemical constituents simultaneously. Attenuated total reflectance FTIR spectroscopy (ATR - FTIR) however is one of the few analytical chemical methods that can be applied directly to complex liquid samples, and is also relatively unaffected by the amount of particulate material in the sample.

In a similar way to the method described by Hashimoto, A. et al. in their journal article entitled "Mid-Infrared Spectroscopic Analysis on Brewed Coffee Characteristics", ATR - FTIR Spectroscopy was applied to a range of different coffee extracts, obtained from different coffee blends, and using three different extraction methods. The results shown in Figures 7-10 show the fingerprint region which highlights some of the main characteristic differences in the various samples, and brewing methods. All transmittance spectra were obtained from coffee extracts produced at the same coffee water ratio, using the same filtered water, with all samples being filtered using the same French press prior to analysis. The FTIR analysis for each sample was performed using a Bruker Tensor 27 ATR-FTIR spectrometer, recording 64 individual scans for each sample and background. The background was established using unprocessed filtered water also as used for the extraction solvent. The units on the X axis are in cm-1. ”CB” represents an extract obtained using a Cold Brew method (e.g. as described in WO2013/019676), wherein cold water was added to the coffee grounds which were subsequently kept below 25°C for 18 hours before being filtered using a French press, and subject to IR analysis. ”FP” (French Press / Cafetiere method) represents an extract obtained using water which was brought to the boil (using a kettle at atmospheric pressure), with the boiled water rested for 30 seconds, before being poured over the coffee grounds. The coffee sample was then stirred and allowed to rest for 4 minutes, before the grinds were separated in the French press and subjected to the IR analysis. "Inv” represents coffee obtained in accordance with the present invention, wherein warm water was added to the coffee grounds, which were then refluxed at 27.1 kPa (8 inHg) for 2 minutes, prior to being filtered in the French press and subjected to IR-analysis. All extracts were prepared using 7g of coffee with 50g filtered tap water, and no additional additives. "Inv F” (figure 9) represents an extract obtained by subjecting an aliquot of the French Press filtered ”lnv” sample to an additional vacuum separation step utilising a prewashed commercial coffee filter paper. The three alternative preparation methods were chosen for comparison, as all the samples can be filtered using the same French press and thereby provides the actual IR sample with a consistent level of particulate matter.

As can be seen from figure 7 (illy coffee - fine, espresso grind), the ratios of the various chemical constituents present in the CB samples differ much more markedly from the FP and Inv samples, with the FP and Inv samples being quite similar. Relative to the FP samples however, the peaks in the Inv samples are significantly sharper and better defined, particularly in the range of 1740-1360 cm-1. PCT/IB2015/055859 WO 2016/038479 33

As can be seen from figure 8, and unlike the spectra shown in figure 7, in this case there is a much greater difference between the FP and Inv samples, particularly in the range of 1740-1360 cm-1. In this case, the coffee beans were coarsely ground in a hand burr grinder under a setting which was deliberately chosen to have a significantly wider particle size distribution than for the commercially ground illy and Caffe L’affare samples. The Inv sample in figure 8 however still largely resembles the characteristic shape presented for the Inv illy sample in figure 7, whereas the FP sample in figure 8 shows a significantly reduced complexity for the pattern of the peaks relative to the corresponding IR spectrum in figure 7. Similarly, the CB sample also shows less complexity in the pattern of the spectrum of figure 8 (e.g. in the region of 1720-1620 cm-1) relative to either of the illy (figure 7) or Caffe L’affare samples (figure 9) which both had a smaller average particle size, and much narrower particle size distribution.

From figure 9, it can be seen that the Caffe L’affare samples (relatively narrow particle size distribution / marketed for drip filter and French press) also show many of the same characteristic peak patterns as shown in figures 7 and 8 for the same respective brewing methods. Figure 9 also includes an additional IR spectrum which was derived from the Inv sample which was additionally filtered through a filter paper so as to remove some of the additional particulates that pass through the stainless steel mesh of the French press. The Inv and Inv F samples still largely shadow each other which suggests that other than a slight reduction in intensity, the impact of the filter paper on the chemical profile of the coffee is actually quite minimal.

Comparison of the differences and similarities in terms of flavour and IR characteristics between coffee extracts obtained by the French Press (FP) method and coffee extracts obtained in accordance with the present invention, reveals that the flavour profile of beverages obtained in accordance with the present invention have less bitterness, yet they still have a similar infra-red chemical profile in the range from 800-1600cm-1; i.e. the present invention provides coffee extracts with less bitterness but which are obtained without substantially altering the overall chemical profile and/or the flavour balance of the coffee extract.

In figure 10, the same data for the three coffee spectra extracts obtained in accordance with the present invention (illy - Inv, HB - Inv and CL - Inv) are overlaid, with the significant peaks being as recited in Table 1. Figure 10 in particular, shows that although the coffee extracts were obtained from three different commercial sources, and which were also roasted and ground independently; the chemical profile of the extracts obtained by the inventive process are however nonetheless very similar.

In particular, it is noted that the two peaks at 1628±3 cm-1 and 1639±3 cm-1 are generally much more pronounced and consistent in the samples obtained in accordance with the present invention, than seen in the samples obtained by the other two methods. Most importantly however is that, unlike other brewing methods, these results show that the extraction method of the present invention provides a surprisingly comparable level of extraction regardless of the source of the coffee grounds, the particle size and the particle size distribution. The level of extraction that results from the process of the present invention is therefore more consistent than other prior art methods, and the coffee extracts obtained by the inventive process also have a rich flavour which is characteristic of each coffee blend, whilst also having less bitterness.

Significant FTIR Peaks Wavenumber (cm^1) (±5 cm-1) Relative Intensity (weak, medium, strong) 1722 w 1709-1703 w 1691 w 1658 w 1639 m 1628 m 1580 s 1566 s 1551 m 1533 m 1514 w 1502 w 1481 w 1462 w 1443 m 1402 m 1385-1383 s 1279 m 1257 m 1244-1246 m 1149 m 1121 m 1080 s 1036 s 812 w 797 w 779 w 704 m 673 m 652 m WO 2016/038479 PCT/IB2015/055859 34

Table 1

Although the invention has been described in detail, for the purpose of illustration, it is understood that such detail is for that purpose and variations can be made therein by those skilled in the art without departing from the spirit and scope of the invention which is defined by the following claims.

Claims (39)

1. CLAIMS:

   1. A method for producing a coffee extract, the method comprising the steps of: a) providing a coffee brewing vessel comprising an intimate mixture of coffee grounds and an aqueous medium; b) reducing the pressure in the coffee brewing vessel so as to be in the range of 3.4 - 84.7 kPa (1-25 inHg); c) brewing the coffee at reflux whilst maintaining the pressure in the range of 3.4 - 84.7 kPa; and d) increasing the pressure in the coffee brewing vessel to atmospheric pressure.
2. 2. The method of claim 1, wherein the method is for producing a coffee extract with less bitterness, wherein at least some of the compounds that impart bitterness are selectively thermally degraded and/or chemically reacted.
3. 3. The method of claim 1 or 2, wherein prior to step c), the method further comprises a step b’) of heating the contents of the coffee brewing vessel whilst maintaining the pressure in the range of 3.4 - 84.7 kPa (1-25 inHg).
4. 4. The method of any one of claims 1-3, wherein the pressure in the coffee brewing vessel is preferably in the range of 13.5 - 67.7 kPa (4-20 inHg), more preferably between 23.7 kPa and 50.8 kPa (between 7 and 15 inHg), and most preferably between 27.0 and 40.6 kPa (10 ± 2 inHg).
5. 5. The method of any one of claims 1-4, wherein after step c) but prior to and/or during step d) the extracted coffee grounds are separated from the extracted aqueous medium.
6. 6. The method of any one of claims 1-4, wherein the extracted coffee grounds are separated from the extracted aqueous medium only after step d) .
7. 7. The method of any one of claims 5 or 6, wherein the extracted coffee grounds are separated from the extracted aqueous medium by a process of vacuum separation.
8. 8. The method of any one of claims 1-7, wherein prior to step a) the coffee grounds are obtained by freshly grinding roasted coffee beans.
9. 9. The method of any one of claims 1-7 wherein prior to step a) the coffee grounds are provided in the form of a substantially anhydrous prepackaged coffee product, which optionally further comprises one or more additives.
10. 10. The method of claim 9 wherein the prepackaged coffee product is intended to be consumed in a single extraction process for preparing a single coffee beverage, and comprises between 5 and 18 grams of coffee grounds.
11. 11. The method of any one of claims 1 to 10, wherein the method is performed such that the coffee extract and/or the coffee grounds are not exposed to a temperature in excess of 80°C, and preferably not in excess of 75°C.
12. 12. The method of any one of claims 1 to 11, wherein in step a) the coffee grounds and the aqueous medium are provided in a weight ratio of from 1:2.78 to 1:50.
13. 13. The method of claim 12, wherein the ratio ranges from 1:25 to 1:50, preferably from 1:28 to 1:38.
14. 14. The method of claim 12, wherein the ratio ranges from 1:2.78 to 1:10, preferably from 1:5.8 to 1:6.8.
15. 15. The method of any one of claims 1-14, wherein step c) is sustained for a period of time between 10 seconds and 30 minutes, more preferably between 1 and 5 minutes, and most preferably at 2 minutes ± 30 seconds; and wherein commencement of the period of time is determined from the point at which the aqueous medium reaches its water reflux temperature.
16. 16. The method of any one of claims 1-15, wherein the coffee brewing vessel during step c) further comprises one or more additives.
17. 17. The method of claim 16, wherein the one or more additives are selected from the group consisting of milk, including fresh milk, UHT milk or cold pasteurised and/or filtered milk; milk powder; cocoa; chocolate; natural sweeteners, including refined, unrefined or partially refined sugar; synthetic sweeteners; flavour enhancers; flavourants, including flavoured syrups; essential oils; fruit juice; fruit pieces; herbs; spices; vitamins; minerals; pharmaceutically active compounds; preservatives; colourants; thickeners; foaming agents and combinations thereof; and wherein the one or more additives are more preferably selected from the group consisting of refined, unrefined or partially refined sugar; chocolate; cocoa; vanilla; salt; cinnamon; orange oil or orange peal.
18. 18. The method of any one of claims 1-17 wherein the coffee grounds, the coffee extract and the aqueous medium are not placed in contact, or able to make contact with any metal objects during the performance of the method.
19. 19. The method of any one of claims 1-18 wherein the method is either partially or completely automated.
20. 20. A method of making a coffee extract comprising: brewing at reflux in a coffee brewing vessel, an intimate mixture comprising coffee grounds and an aqueous medium, wherein the pressure in the coffee brewing vessel is pumped down into the range of 3.4 - 84.7 kPa (1-25 inHg).
21. 21. The method of any one of claims 1-20 wherein the pressure in the coffee brewing vessel is achieved utilising a hand operated vacuum pump, or an automated and/or electrically powered vacuum pump.
22. 22. The method of any one of claims 1-21 wherein during the brewing step, a substantial portion of any condensable vapours that leave the coffee brewing vessel are condensed utilising an external source of water or air, and the resultant condensate is allowed to return back to the coffee brewing vessel.
23. 23. A coffee extract with less bitterness obtained and/or obtainable by the method of any one of claims 1-22.
24. 24. Use of the coffee extract with less bitterness according to claim 23, for making a coffee beverage, for making a food product, or for making a dried instant-coffee product.
25. 25. A coffee reflux extraction apparatus comprising: a coffee brewing vessel; a cannula; one or more vacuum pumps for reducing the pressure in the coffee brewing vessel to the range of 3.4 - 84.7 kPa (1-25 inHg); a steam condensing means having an evacuation means; and a collection vessel having a collection vessel evacuation means; wherein the apparatus is configured for the extraction of coffee grounds at reflux for a predetermined time period at a pressure in the range of 3.4 - 84.7 kPa (1-25 inHg); and wherein the apparatus is further configured to subsequently transfer hot liquid from the coffee brewing vessel into the collection vessel via the cannula under the action of a pressure differential provided by one or more of the vacuum pumps and mediated through said evacuation means.
26. 26. A coffee reflux extraction apparatus comprising: a coffee brewing vessel; a cannula; one or more vacuum pumps for reducing the pressure in the coffee brewing vessel to the range of 3.4 - 84.7 kPa (125 inHg); a steam condensing means having an evacuation means; a filter vessel having a filter and at least one filtrate outlet for connection to a collection flask; wherein the filtrate outlet further comprises a filtrate evacuation means; and wherein the coffee brewing vessel and the cannula are configured to transfer an aqueous medium contained in the coffee brewing vessel to the filter vessel via the cannula under the action of a pressure differential provided by one or more of the vacuum pumps and mediated through said evacuation means.
27. 27. A coffee reflux extraction apparatus according to claim 25 or claim 26, wherein the distance between the bottom of the cannula and the lowest inside surface of the coffee brewing vessel is 1500 micrometres (microns) or less, and preferably 500 micrometres ±300 micrometres.
28. 28. A coffee reflux extraction apparatus according to any one of claims 25-27, wherein the evacuation means and filtrate evacuation means can be pressure equalised under reduced pressure.
29. 29. A coffee reflux extraction apparatus according to any one of claims 25-28, wherein the steam condensing means further comprises a gas inlet that allows the pressure in the coffee brewing vessel to be increased.
30. 30. A coffee reflux extraction apparatus according to any one of claims 25-29, wherein polytetrafluo-roethylene (PTFE) is used to minimise any leaks between joints of the coffee reflux extraction apparatus.
31. 31. A coffee reflux extraction apparatus according to any one of claims 25-30, wherein the apparatus is free of any metal parts or components which may impart undesirable flavours to the coffee extract.
32. 32. A method of any one of claims 1-22, wherein the method is performed in the coffee reflux extraction apparatus as defined in any one of claims 25-31.
33. 33. A coffee reflux extraction apparatus for performing the method of any one of claims 1-22, wherein the apparatus comprises: a coffee brewing vessel in communication with a heat source; a steam condensing means; and a vacuum pump; wherein the apparatus is configured to sustainably condense water vapour in the temperature range of between 25 and 95°C for at least 90 seconds, and to provide a means for returning the condensed water back to the coffee brewing vessel.
34. 34. A coffee reflux extraction apparatus when used to perform a method of making a coffee extract; wherein the method comprises: brewing at reflux in a coffee brewing vessel, an intimate mixture comprising coffee grounds and an aqueous medium, wherein the pressure in the coffee brewing vessel is pumped down into the range of 3.4 - 84.7 kPa (1-25 inHg).
35. 35. The coffee reflux extraction apparatus according to claim 34, wherein the apparatus comprises: a coffee brewing vessel in communication with a heat source; a steam condensing means; and a vacuum pump; wherein the apparatus is configured to sustainably condense water vapour in the temperature range of between 25 and 95°C for at least 90 seconds, and to provide a means for returning the condensed water back to the coffee brewing vessel.
36. 36. Use of a coffee reflux extraction apparatus in a method of producing a coffee beverage, wherein the method comprises: brewing at reflux in a coffee brewing vessel, an intimate mixture comprising coffee grounds and an aqueous medium, wherein the pressure in the coffee brewing vessel is pumped down into the range of 3.4 - 84.7 kPa (1-25 inHg).
37. 37. A method for producing a coffee extract under reduced pressure substantially as herein described, with or without reference to any of the examples and/or drawings.
38. 38. A coffee reflux extraction apparatus for producing a coffee extract under reduced pressure substantially as herein described, with reference to any of figures 2-6.
39. 39. Any novel invention as claimed herein or elsewhere.