WO1999050383A2

WO1999050383A2 - Micro-brewing device

Info

Publication number: WO1999050383A2
Application number: PCT/GB1999/001023
Authority: WO
Inventors: Anthony Fenwick-Wilson
Original assignee: The Miracle Beer Company Limited
Priority date: 1998-04-01
Filing date: 1999-04-01
Publication date: 1999-10-07
Also published as: GB9807055D0; AU3338899A; GB2335902A; WO1999050383A3; WO1999050383B1

Abstract

A brewing device for home brewing has a pressure vessel (3) containing a flexible liner which is disposable and provides a sterile interior to the pressure vessel (which is itself not disposable). The vessel is pressurized by a bellows type dispensing pump (7) to allow the brewed liquid to be discharged through a dispensing tube (9). The dispensing tube (9) is preferably disposable as are all other components which come in contact with the liquid fermenting within the liner. The device includes a pressure relief valve to limit the dispensing pressure to a value consistent with best foaming of the beverage being dispensed.

Description

MICRO-BREWING DEVICE

The invention relates to a new small scale device for brewing beer and other fermentation beverages at home by consumers. It is especially designed to provide a reusable apparatus which particularly avoids the problem of contamination which requires careful sterilisation before re-use.

By the term "fermentation beverages" we mean drinks such as:- beer, for example lager, bitter, wheat beer or stout; barley wine; cider; so-called "alcopops" (alcoholic lemonade type drinks); and wine.

Small scale equipment for brewing at home by consumers is well known. Several of such products have appeared on the market in recent times, but for various reasons none of them have been entirely successful. One of the most important aspects for brewing is the sterility of all the parts and surfaces in contact with the brewing medium. So far the only satisfactory ways of avoiding this problem are either by a complicated and wearisome sterilisation process or by designing equipment to be disposed of after use. Sterilisation is difficult for the consumer to complete satisfactorily, and removes the convenience which is one of the more important features of brewing at home. Use of improperly sterilised equipment produces a resulting beverage which is of inconsistent and very poor quality, even if palatable. Palatability is of course a subjective quality.

The disposable systems have generally been unsatisfactory for other reasons:

a) difficulty of pressurisation b) sediment c) complexity of process

For example the "portable brewery" system marketed by the Soda Stream company was not pressurised. Dispensing was from a tap by gravity, which resulted in varying dispensing rates depending on the head of liquid remaining. The sediment did not always clear, providing a second problem.

A device known as "Mr Brewer", marketed by Ritchie Products Ltd of Burton-on- Trent, England, was vented to prevent over-pressurisation, but this resulted in the beer produced being de-gassed or flat. Dispensing can then only be achieved by physically collapsing the inner sack. To carbonate the beer it was necessary to pressurize it with an external source of compressed gas.

"Dry Home Brew" kits, using standard buckets and fermentation vessels, for example, do produce more consistent results but these use multi-stage processes which require several vessels.

The present invention aims to overcome these problems by using a small, rigid, re-usable apparatus designed to accept a disposable inner flexible bag and other contact parts. Thus the parts that are in contact with the liquid are discarded after use and avoid the problem of sterility.

Accordingly, one aspect of the present invention provides brewing apparatus comprising a pressure-resistant vessel, a dispensing pump having an air outlet communicating with the interior of the vessel for pressurizing liquid in the vessel, and a pressure relief valve for venting excess dispensing pressure to limit the dispensing pressure to a desired maximum value.

Thus the system is designed to create pressure, to retain it, and to maintain it and relieve any excess. The apparatus may have bellows pump that is used to maintain pressure while dispensing.

Preferably it also incorporates a second pressure relief valve designed to open at pressures different from that of the first mentioned valve, thus acting as a back-up to avoid any possibility of unsafe pressures being produced. A second aspect of the invention provides brewing apparatus comprising a pressure-resistant vessel, a flexible gas- and liquid-tight container having an opening for admission and discharge of liquid and being dimensioned to fit within the vessel to serve as a liner therefor, a closure for said opening in the liner, a discharge conduit adapted to have one end within the liner and the other end outside the vessel for communicating the interior of said flexible container with the exterior of said vessel, and flow control means to control dispensing flow of liquid by way of said discharge conduit, wherein the liner, and the closure for the liner are disposable after dispensing of the brewed liquid from within the liner.

Preferably the disposable closure for the liner includes a disposable non-return valve to allow pressurizing gas into the liner to establish fermentation pressure in the liner within the vessel.

A third aspect of this invention provides a method of brewing a fermentation beverage, comprising taking a vessel capable of withstanding the pressures arising during fermentation of the beverage, placing a disposable flexible liner within the vessel, covering the vessel with a cover plate to enclose the interior of the liner to avoid ingress of pollutants from outside the liner, inserting a dispensing tube sealingly through said cover plate and into the liner within said vessel, placing ingredients for brewing within said liner and maintaining it in a sealed condition during fermentation so as to allow anaerobic fermentation to take place, and after fermentation pressurizing the interior of said liner and allowing discharge of the fermented beverage, wherein, after completion of dispensing of the fermented beverage, the liner, and the cover plate are disposed of and replaced by sterile fresh similar components before a next successive batch of the beverage is fermented. Preferably the pressurizing of the interior of the liner is carried out through a disposable non-return valve which is replaced by a fresh one before said next successive batch is fermented.

In orderthat the present invention may more readily be understood the following description is given, merely by way of example, with reference to the accompanying drawings in which:-

FIGURE 1 is a side elevational view of the brewing apparatus of the invention when fully assembled;

FIGURE 2 is a perspective view of the pressure vessel of the apparatus of Figure 1 after removal of the bellows pump and the top cover, and before installation of the flexible dispensing hose.

FIGURE 3 is a perspective view of the neck collar of the disposable bag liner which fits within the spherical body of the device shown in Figures 1 and 2;

FIGURE 4 is a side elevational view of the container (bottle) for enclosing the powdered ingredients and for use in mixing the ingredients with water at the start of the brewing process;

FIGURE 5 is a perspective view of a cover plate which closes the neck of the bag, in use, and receives the flexible dispensing hose from within the bag as well as allowing pressurizing air to be introduced into the bag;

FIGURE 6 is a sectional view of the cover plate taken on the line 6-6 of Figure 5;

FIGURE 7 is a sectional view showing the assembly of the bag neck collar of Figure 3 and the cover plate of Figures 5 and 6, both held down by a threaded retainer on the neck of the top pressure vessel wall visible at the top of Figure 2;

FIGURE 8a illustrates the flexible dispensing hose;

FIGURE 8b is a sectional view of the central body between the two flexible ends of the dispensing hose;

FIGURE 9 is a sectional view of the air inlet valve to the disposable bag liner;

FIGURE 10 is a detail, in the form of a sectional view, of the pump air intake valve formed in the lid shown in Figure 2;

FIGURE 11 is a perspective view of the threaded retainer shown in Figure 7, but illustrating the dispensing clamp thereon;

FIGURE 12 is a side elevational view of the bellows pump;

FIGURE 13a a perspective view of the cap visible at the top of the apparatus shown in Figure 1 (on which the bellows pump is seated);

FIGURE 13b is a schematic sectional view of the cap of Figure 13a, showing the valve body of the air intake valve of Figure 10; and

FIGURE 14 is a schematic sectional view of an alternative embodiment of brewing and dispensing apparatus.

Referring now to the drawings, Figure 1 shows a brewing and dispensing apparatus (to be known under the Trade Mark "Brewzer") as comprising a part- spherical vessel 3 blow-moulded of high density polyethylene, and a cap 5, also formed of polypropylene, atop the vessel 3. A bellows pump assembly 7 sits atop the cap 5 and can serve for pressurizing the contents of the vessel for dispensing those contents. In practice the vessel can be used for brewing beer of various types, or cider, or alcoholic "pop" beverages, or equally for wine making.

It is an important feature of the present invention that fermentation takes place within a disposable plastic bag which serves as a barrier to carbon dioxide and which has associated with it an inlet valve for air and an outlet port to receive the dispensing hose 9 visible in Figure 1. All of these components will be in contact with the fermented liquid during fermentation and/or dispensing, and it is contemplated that they will therefore all be disposable in order to avoid the need for sterilization of the interior of the vessel after dispensing of one batch of the brew and before fermentation of the next batch. Other than the hose 9, the components visible in Figure 1 are non-disposable and are designed to withstand the pressure which will be generated during fermentation and which is required during dispensing.

Figure 2 shows the vessel 3 of Figure 1 after removal of the part-spherical cap 5, exposing a top wall 12 supporting an externally threaded rim 11 the purpose of which will be described below.

Figures 1 and 2 both show that the underside of the spherical vessel 3 is provided with a plurality of hemispherical protrusions 13 formed integral with the body 3 during the blow-moulding process and serving as stabilizing feet for the vessel. More importantly, they also provide cavities into which the flexible carbon dioxide barrier bag will settle when filled with liquid, to define a plurality of recesses in which the sediment will preferentially form during the fermentation process. By having the sediment thus partly confined within these recesses it is possible to ensure that during the dispensing operation the sediment will not be unduly agitated and entrained by the dispensing flow. There are at least three of these "feet" 13, and preferably five of them. Figure 3 shows the flexible carbon dioxide barrier bag 15 with its welded-on collar fitment 17 defining a retaining flange 19 which ensures that the bag neck can be held in the aperture defined by the externally threaded rim 11 of the vessel 3 (Figure 2). The collar fitment 17 can be attached by any suitable welding process. The arrangement is such that the bag 15 can be collapsed into an elongate "sausage-like" shape to allow it to be threaded into the opening defined by the rim 11 of Figure 2, and equally to allow the bag 15 to be withdrawn once the contents of the bag have been dispensed. Although not shown in full, the flexible bag 15 is made of nylon polyethylene laminate of 60 micron gauge, and is of a size to fully take up the shape of the outer vessel 3 when pressurised, without any undue stress in the flexible material. The bag 15 may have a square (gusseted or ungusseted) form or a rounded form.

Figure 4 shows a different component of the system and comprises a bottle 21 of blow-moulded low density polyethylene formed with a screw-threaded neck 23 to receive a screw cap 25. The bottle 21 forms part of a replenishment kit for the device and will be sold together with a set of each of the other disposable components. The bottle, when sold, will already include a charge of powdered ingredients which comprise a ready mixed product having as basic ingredients hops, malt extract, and yeast.

Figure 5 shows a cover plate 27 which sits atop the threaded rim 11 (Figure 2) of the vessel 3 and includes a downwardly extending integral collar 29 receiving the flexible dispensing hose 9 of Figures 1 and 8a, as well as an upwardly extending collar 31 receiving the air discharge tube of the bellows pump assembly 7 shown in Figures 1 and 12.

Figure 6 is a sectional view taken on line 6-6 of Figure 5 and illustrates the downwardly extending collar 29 and the upwardly extending collar 31 , as well as a one-way valve 33 allowing flow upwardly through the cover plate 27 but only when a predetermined threshold pressure has been achieved. For brewing the type of beer known as bitter the preferred threshold venting pressure for the valve 33 is 6 psi (41.4 KPa) but other pressures may be required depending on the nature of the beverage being brewed. Even for brewing beers there will be available valves 33 of different threshold pressures. By selling the partition fitment 27 together with the rest of the disposable items and the mixing bottle 21 , it is possible to ensure that the threshold venting pressure of the valve 33 is appropriate to the nature of the beverage to be brewed using the particular powdered ingredients in the bottle sold with it. It may also be advantageous to colour code the valves 33 to match a label of the bottle 21 to ensure the appropriate relief pressure is provided.

As shown in Figure 7, the collar fitment 17 of Figure 3 fits comfortably in the annular rim 11 of the pressure vessel top wall 12 shown in Figure 2, and then the cover plate 27 of Figures 5 and 6 is placed on the top flange 19 of the collar fitment 17. When the threaded retainer 35 is screwed down on to the assembly of the cover plate 27 and the collar fitment 17, a sealing action is formed between the underside of the cover plate 27 and the top flat face of the flange 19 of the bag collar fitment 17, and the bag 15 is then securely held in place by its collar fitment 17. It is dimensioned so that, when the bag 15 is pressurized for dispensing or, initially, when the bag 15 is filled with liquid, the bag conforms to at least the lower part of the interior of the vessel 3 but leaves an adequate gas space within the liner above the liquid.

Figure 8a shows the preferably corrugated flexible discharge hose 9 having a first end 37a which is inserted down through the downwardly extending collar 29 of the cover plate 27 (Figures 5 and 6) to reach near the bottom of the interior volume of the vessel 3 (now lined by the bag 15), while its other end 37b is located outside the vessel and constitutes the free end of the flexible dispensing hose 9 shown in Figure 1. The majority of the hose 9 is of corrugated form providing a ribbed surface both internally and externally, with the advantage that the flow of brewed liquid out through the corrugated hose 9 undergoes minor turbulence over the internal ribbing and is suitably mixed and aerated to provide a pleasing head of foam on the dispensed liquid (for example beer). The fact that some of the dispensed liquid may deposit in the corrugated tube is of no consequence because the entire hose 9 is part of the disposable kit of the apparatus.

Between these two corrugated hose portions is a central fitting 39, shown in more detail in Figure 8b. This has, at its upper end, a stop catch 41 of sawtooth cross-section and, at either end, a fitment 43 which fastens to the respective corrugated hose portion. At a distance below the underside of the saw-tooth stop flange 41 is an outwardly extending bead 45 which frictionally engages the interior of the downwardly extending collar 29 to hold the hose in place in the cover plate 27.

This frictional holding of the fitment 39 in the collar 29 provides a pressure relief valve effect in that, even when the hose 9 is blocked to prevent escape of gas or liquid from within the bag 15, the fitment 39 will be held in the collar 29 securely enough to withstand a pressure differential rather higher than the threshold venting pressure of the one-way pressure relief valve 33 of the cover plate 27. For example, the fitment 39 may be retained frictionally in the collar 29 until an internal pressure within the bag 15, reinforced by the part-spherical wall of the pressure vessel 3, rises to 20 psi (138 KPa). Given that pressure tends to build up during the fermentation action, and that during fermentation the flexible dispensing hose 9 will be closed off, by means to be described later, it is important to ensure there is some means of preventing rupture of the bag 15 and/or the pressure vessel 3 in the event of excessive internal pressure and this is achieved by virtue of the pressure relief action of the frictional hold of the bead 45 in the collar 29. A pressure other than 20 psi (138 KPa) may of course be chosen but it is expected that where there are two separate relief valves 33 and 45, 29 the pressure of the frictional holding of the dispensing tube by "valve" mechanism 45, 29 will be higher than the venting pressure of the other valve whose venting pressure is related to the required dispensing pressure of the finished beverage.

Figure 12 shows the bellows pump assembly 7 as having two plain air tubes 47 and 49, such that the longer tube 47 fits within the upwardly extending collar 31 but with the interposition of a one-way "umbrella" valve 51 shown in Figure 9. Although not shown in the assembled form, the operation of installing the bellows pump delivery tube 47 in the collar 31 requires firstly the placing of the thimble shaped valve body 53 of the air delivery valve 51 (Figure 9) in the upwardly extending collar 31 of the cover plate and then application of the bellows pump 7 to the assembly by forcing the air delivery tube 47 of the bellows pump sealingly into the interior of the thimble-shaped valve body 53 of the air discharge valve 51.

The air discharge valve 51 includes a valve member having a stem 55 with, at its outer end, an umbrella-shaped head 57 and, at its inner end, an enlarged head 59 to prevent the valve member 55-59 from escaping from the thimble- shaped valve body 53. When the bellows pump assembly 7 is compressed, with its air intake tube 49 closed as will be explained shortly, the air within the bellows is expelled through the air discharge tube 47 and the valve 51 to drive the valve member 55-59 downwardly and thereby to open the various part- annular vent ports 61 of the thimble-shaped valve body 53 to allow that air to pass into the interior of the bag 15. When the bellows pump assembly 7 is relaxed, with the air inlet tube 49 open, entry of air through the air discharge valve 51 is prevented as any initial inflow of air lifts the valve member 55-59 to bring the flat upper face of the umbrella-shaped valve head 57 flush with the underside of the end panel of the thimble-shaped valve body 53 such that the supple material of which the valve member 55-59 is formed will sealingly close the ports 61. The air inlet valve 51 may, if desired, be an integral part of the cover plate 27 and hence discarded upon disposal of the cover plate. It will of course be understood that the various valve ports 61 shown in Figure 9 define segments of an annular slot, with the adjacent segments separated by bridging pieces to hold the central part of the end wall of the thimble-shaped valve body 53 in place.

The above-mentioned opening and closing of the air inlet tube 49 of the bellows 7 is achieved by virtue of a further one-way valve 63 shown in Figure 10. This valve 63 includes an outer thimble-shaped valve body 65 having at its upper end integral with the pressure vessel top wall 12 of Figure 2 and having at its lower end part annular air ports 69 similar to the ports 61 of the valve 51 shown in Figure 9. In this case, the valve member is an annular washer-shaped member of suitably supple form to effect the required sealing of its underside against the upper surface of the lower end wall of the thimble-shaped valve body 65, and the arrangement is such that the periphery of the washer-shaped valve member 71 is greater than the periphery defined by the part-annular air ports 69 while the diameter of the central bore 73 of the washer-shaped valve member 71 is smaller than the diameter of the central panel 75 of the end wall of the thimble-shaped valve body 65. Lifting movement of the washer-shaped valve member 71 is limited by the lower end of the air inlet tube 49 of the bellows.

As shown in Figure 11 , the screw cap 35 shown in Figure 7 has additionally an integrally formed clamp mechanism comprising a clamp anvil 77 against which a pivotable clamp stirrup 79 can be pressed. In order to enable the flexible dispensing hose 9 to be closed off to allow anaerobic fermentation to occur, and equally to hold dispensing pressure once the brewing process has been completed, after the dispensing hose 9 has been inserted into the downwardly extending collar 29 of the cover plate 27 of Figures 5 to 7, it is threaded between the raised clamp stirrup 79 and the clamp anvil 77 so as to extend laterally out of the top of the pressure vessel 3. To close off the dispensing hose 9 requires simply downward movement of the clamp stirrup 79 to engage a catch which holds it firmly against the clamp anvil 77 with the flat run of the dispensing hose 9 held clamped closed.

Then, when the beverage within the bag 15 is to be dispensed, and given that there will be a pressurizing effect on the surface of the beverage, it is adequate to lift the clamp stirrup 79 to release the catch holding it against the anvil 77, thereby allowing the flexible dispensing hose 9 to resume its circular cross- section to create a discharge passage for the pressurized contents.

In order to close the assembly shown in Figure 7, a lid 81 is placed over the top wall 12 of the vessel 3 on the rim 4 of the vessel and is arranged such that a cut out 83 of the lid receives and conceals part of the flexible dispensing hose 9. Finally the bellows pump 7 can be placed partially into the upper cylindrical recess 85 of the lid so that its air tubes 47 and 49 project through downwardly extending collars 87 and 89 of the lid 83. This completes the arrangement shown in side elevation in Figure 1.

It will of course be understood that the air intake to the bellows pump 7 is by way of the shorter inlet tube 49 whose lower end is above the cover plate 27 of Figures 5 to 7. Air intake to the pump is therefore by way of the aperture 83 which houses the flexible dispensing hose 9.

On the other hand the delivery of air from the bellows pump 7 is able to pass downwardly through the upwardly extending collar 31 of that cover plate to enter the space within the bag 15.

Likewise, when the dispensing pressure relief valve 33 opens to vent off to the desired maximum dispensing pressure, this vented air escapes to a location above the cover plate 27 and is hence able to escape via the opening 83 in the lid 81. Thus the pump air inlet valve 63 shown in Figure 10 is isolated from contact with the liquid being fermented and dispensed so it forms part of the non-disposable system of the apparatus.

The disposable system comprises the following elements:- (a) the bottle 21 and its screw cap 25 shown in Figure 4;

(b) the bag 15 with its welded-on collar fitment 17, shown in Figure 3;

(c) the dispensing hose 9 shown in Figures 1 , 8a and 8b;

(d) the pump air discharge valve 51 shown in Figure 9, and

(e) the cover plate 27 shown in Figures 5, 6 and 7.

It is intended that the device will initially be marketed complete, and that replacement kits comprising these disposable elements (with the powdered ingredients already present in the bottle 21 ) will be marketed as replacement items which are capable of producing a batch of beverage of the required size.

The outer rigid vessel 3 is designed deliberately in a near spherical shape to allow the smallest size for its volume and well suited to contain internal pressures. It is also advantageous in minimising the settlement of the fermentation sediment outside the hemispherical cavities defined within the feet 13. The five feet 13 on which it stands provide great stability even on surfaces that are not entirely even. Also the series of separate chambers formed by the feet 13 at the bottom of the brew chamber, for the sediment to collect in, considerably reduce the risk of disturbing the sediment produced during the fermentation process and especially of disturbance resulting from any turbulence caused by the dispensing process. The height of the end of the dispensing hose 9 above the base of the vessel 3, and the diameter of this hose 9, are designed to provide the dispensing rates under the specified dispensing threshold pressure that cause minimum disturbance of the sediment while allowing the maximum amount of beer or other beverage to be dispensed, even under the distortion in shape of the vessel 3 caused by internal pressure.

Much consideration has also been given to the process of mixing and adding ingredients. All of the ingredients are supplied in dry powder form in a quantity suitable for 10 pints (5.68 litres) of beer to be produced. This is provided in the plastic bottle 21 with its screw closure 23. The bottle 21 is supplied sterile and is translucent in nature so that the level of contents can be assessed from the outside. A level mark is moulded into this container for the purpose of allowing the addition of cold water to an exact level. When this is done an important air space is then left which allows the ingredients/water mix to be shaken with maximum effect. The contents are then poured into the bag 15 in the vessel 3. The bottle is then again filled with water to the same level, three more times and these further doses of liquid are added to the vessel. The apparatus is then assembled and closed by addition of the cover plate 27, threaded retainer 35, dispensing hose 9, air discharge valve 51 (Figure 9), lid 5 (Figures 1 , 13a, 13b) and bellows pump 7, and left undisturbed until ready for dispensing.

This process is then a simple one step operation, not a multi-staged process as previously known. The pressure vessel 3 of blow-moulded high-density polyethylene is preferably of a size suitable for producing a batch of 10 pints (5.68 litres) of beer, but any rigid material is suitable and the size can be varied to suit the output level required. The flexible bag 15 which contains the liquid is preferably made of a nylon/polyethylene laminate to provide good gas barrier and moisture barrier, but any flexible material with sufficient barrier properties can be used.

The ingredients mixing container does not need to be limited to the bottle 21 described, as any sterile vessel of suitable size, and any water measuring method, would be equally acceptable. Figure 1 shows a sketch of the main outer vessel of the BrewZer it is a near- sphere of moulded high density polyethylene with a flat top incorporating a central opening of 89 mm bore with an external screw thread.

The dry ingredients of various types are supplied in plastic bottles 21 , of the design shown in Figure 4. This bottle 21 is blow-moulded of low density polyethylene and has an internal volume of 2.2 litres and a standard 38 mm diameter plastic screw closure. The bottle incorporates a level indicator of 1950 cc and, when sold for brewing bitter, contains 789 grammes of dry ingredients. Water, preferably potable tap water, is added up to the indicated level. The cap 23 is replaced and the bottle is inverted and shaken energetically for about 60 seconds to ensure good dispersion. The cap is removed and the contents transferred to the flexible bag 15 with the vessel 3. The bottle 21 is then re-filled three times to the same indicated level with potable/cold tap water which is also added to the bag 15 in the vessel. The bottle 21 is supplied sterile when filled with dry ingredients and closed. The level mark of 1.95 litres is designed to provide the correct amount of water, and the air space left of 250 cc above the water level in the bottle is designed to allow maximum effect of dispersion when shaken.

The cover plate 27, Figure 5 and 6, supplied with the dispensing hose 9 Figure 8a, and pressure relief valve 33 is placed over the opening in the collar fitting 17 of the bag.

The air space above the liquid in the vessel 3 is adequate to accommodate the foam forming during fermentation, without the foam coming into contact with the cover plate 27. Equally the air space must be adequate to allow for the air pressurisation action using the pump assembly 7 to work without over frequent pumping being needed (because of too small an air space). The gland retainer 35, with its hinged clamp stirrup 79 in the open position as shown, is then placed over the hose 9 and screwed on to the neck rim 11 which then holds the whole assembly in position as shown in section in Figure 7 (where the hinged clamp stirrup of the gland retainer is omitted for reasons of clarity).

The dispensing hose 9 is then folded down and through the stirrup 79 and placed on the anvil 77 of the gland retainer 35. The stirrup 79 is then hinged down onto the anvil 77, pinching the dispensing tube closed and holding it in position.

The lid 5, Figures 13 and 13b, containing the non-return air inlet valve 63, Figure 10, and the one way air valve 53, Figure 9, is then placed over the assembly and shaped into position and held by means of moulded-in clips (not shown).

The bellows pump 7, Figure 12, is inserted into the recess in the lid 5 so that the tubes 47, 49 in its base enter into the appropriate valves 63 and 53.

The "BrewZer" apparatus is now assembled, Figure 1 , and is left undisturbed for a period of, for example, 2 weeks, when it is ready for dispensing the beer. For obtaining a bright product (one which does not suffer from visible protein haze) a period of one to two weeks longer should be allowed before dispensing.

The pressure relief valve 33 in the cover plate 27 is a propriety valve "VERNAY umbrella valve VA 3497". The one way air valve 51 , Figure 9, is also a proprietary valve 'VERNAY umbrella valve VA 3405".

Dispensing is effected very simply through the hose 9 by means of operating the clamp 77, 79. Dispensing is at first effected by internal pressure, which is then maintained by pushing the bellows pump 7, as required, when the contents are depleted. The sediment remains in the "feet" 13 during the dispensing of the liquid brew. Once empty the BrewZer vessel 5 is then disassembled, the cover plate 27 with the valves 33, 53 and the hose 9 is then discarded complete, as is the flexible bag 15 containing the sediment. The BrewZer apparatus is then ready for re-use.

Figure 14 shows an alternative embodiment which is suitable for construction on a larger scale. This may, for example, be used as a brewing unit for a "micro-brewery" application where a hotel or bar brews its own alcoholic drink, for example beer, in batches such that one batch is being dispensed for consumption while the next batch is being brewed.

The components of Figure 14 which are identical to, or serve the same purpose as, corresponding parts in the earlier embodiments use the same reference numeral but increased by 100.

The apparatus comprises a cylindrical container 103, for example of injection moulded plastic construction, topped by a neck-defining member 104 which may be bonded to the rim of the container 103 by any suitable means, for example ultrasonic welding. This neck-defining member 104 has an upstanding externally threaded neck to which is threadably attachable an internally threaded clamping ring 106.

The clamping ring 106 is provided in its underside with a cylindrical sealing gasket 108 to ensure that when the clamping ring is screwed down the assembly of the neck-defining ring 104, the clamping ring 106, and the components held down by it, provides a sealing closure to the container 103.

The interior of the container 103 includes a disposable plastic film bag 115 welded to a neck ring 117 which seats on the upper end of the neck of the component 104. Immediately above this neck 115 is a disposable cover plate 127 having an integrally formed mounting sleeve 131 which extends downwardly, to support a dip tube 1002 which extends into the interior of the bag 115 to a location down near the floor of the container 103, and also extends upwardly, to form a mounting for the delivery tube 109. In this case the delivery tube 109 is provided with an integral dispensing valve 110 at its delivery end. The dispensing tube 109 may, as in the case of the earlier embodiments, be of corrugated form although this is not illustrated in Figure 14.

Also defined in the cover plate 127 is a pressure relief valve 133 equivalent to the valve 33 of Figure 6.

The cover plate 127 also has a downwardly extending cup 129 which includes in its base a non-return valve 157 to define the outlet valve of a pressurizing means in the form of dispensing bellows 107 which has a plug portion received sealingly in the cup 129. For disposal of the cover plate 127 with its non-return valve 157, the plug portion of the bellows 107 is able to be removed from the cup 129 to allow the bellows to be re-used.

In this larger capacity apparatus the ingredients come already located within the bag 115, and for this purpose some seal means such as a membrane seal welded across the mouth of the neck fitting 117 of the bag may be provided.

As in the earlier embodiments, the cover plate 127 with the pressure relief valve 133 and the mounting sleeve 131 is disposable at the end of dispensing each batch, and likewise the dip tube 108 and the separate dispensing tube 109 will be disposable.

One significant difference between the embodiment of Figure 14 and those described above is that the non-return valve 157 is itself a disposable component in that it is mounted in the cup 129 forming an integral component of the disposable cover plate 127. ln use of the apparatus of Figure 14, the clamping ring 106 is removed from the threaded neck of the neck component 104. At this stage there will be no cover plate 127 in place. Any seal on the bag neck fitting 117 is then removed to gain access to the interior of the bag and the bag is then inserted through the neck of the component 104 until the neck fitting 117 is seated in the position shown in Figure 14. (Where the seal of the neck fitting 117 is a welded membrane across the mouth, it is possible to delay removal of that seal until the bag has been inserted into the container 103 and the neck fitting is in the Figure 14 position.)

Then the desired quantity of water is added to the interior of the bag 115 to cause the bag 115 to expand into intimate contact with the interior of the container 103. The required volume of water may either be indicated by a marking on the apparatus to indicate the "full" level, or the volume may be a known quantity which can be measured into the bag.

Then a clean cover plate 127, together with the dip tube 102 and the discharge tube 109 and dispensing valve 110, is removed from within any hermetic packaging and the dip tube and the delivery tube are then fitted on to the mounting sleeve 131 to the configuration shown in Figure 14. At this stage the mounting plate 127 is then placed over the neck fitting 117 and is clamped in position by addition of the clamping ring 106 which is screwed down firmly so that the sealing gasket 108 becomes compressed against the upper surface of the cover plate 127.

Finally the bellows 107 is mounted in position on the cover plate 127 by inserting its plug portion forcibly into the cup 129. Then the bellows are operated to effect pressurization of the interior of the bag 115 to brewing pressure. This may be indicated by venting through the pressure relief valve 133 once the appropriate brewing pressure has been attained. The apparatus is then allowed to stand for the required brewing time for anaerobic fermentation to occur within the enclosure defined by (i) the bag 115, (ii) its neck fitting 117, (iii) the cover plate 127, and (iv) the delivery tube 109 and closure valve 110.

As indicated above, it is possible for the bellows 107 to be dispensed with and for a source of inert gas, for example a bottle of liquid nitrogen, to be used to pressurize to brewing pressure. Equally such a source of pressurized gas will be used to dispense the brewed liquor when desired. The pressurized dispensing of the finished brew is carried out in the same way as for the earlier described embodiments.

Where such a source of pressurized inert gas is used, the bottle of gas needs to be connected to a just-charged brewing container for long enough to allow its pressurization to brewing pressure, afterwhich that same gas bottle can then be transferred to a similar container in which fermentation is already complete and dispensing under pressure is required.

With this form of the apparatus, which is particularly suitable for use in a bar where the brewed beverage may be sold directly to the consumer in the manner of draught beer (which traditionally pumps the beer from a bulk storage container through a dispensing nozzle on the counter of the bar), it is also preferable to incorporate a cooling means in the delivery line from the container which is dispensing the brew, i.e. between the dispensing container and the dispensing nozzle of the tap. Any suitable cooling means may be used for this purpose. The equipment would then consist of at least two brewing containers, one of which can be dispensing while the or each other one is in brewing mode, a source of gas under pressure, able to be connected releasably to each of the containers so as to achieve both the pre-brewing pressurization and the post- brewing dispensing pressure, and a delivery line with the dispensing tap and cooling means, and able to be connected releasably to each of the containers so that as they in turn become the dispensing container the dispensing line can be readily detached.

Where the pressurization is achieved by virtue of the bellows, it is normal for the bellows to remain attached to the cup 129 throughout the brewing process and the dispensing stage. However, because the pressurized interior is sealed by virtue of the non-return valve 157 it is equally possible for one bellows to be used for both (i) charging one brewing vessel and (ii) dispensing from another vessel in which fermentation has already been completed.

Once the dispensing operation is complete the bellows 107 is removed, the clamping ring 106 is unscrewed, and the cover plate 127 with the tubes 102, 109, and also the bag 115 and neck fitting 117, with any fermentation residue left in the bag, are all disposed of, for replacement by completely fresh hygienically packaged components before the next brewing operation.

The use of a non-return valve as part of the disposable cover plate assembly can also be incorporated in the earlier described embodiments simply by redesigning the mounting sleeve 29 for the bellows non-return valve so as to have its own integral non-return valve, in which the arrangement will be the same as that of Figure 14 in that the bellows need only provide a sealing engagement with the sleeve 29 and not a non-return function.

Both of the family of embodiments described herein use a common feature of anaerobic fermentation (in that even where the air-pressurizing bellows 7, 107 is used to provide the brewing pressure the release of carbon dioxide during the fermentation process will result in flushing of the initial charge of air from the interior of the bag until the gas above the fermenting liquor is substantially free of oxygen) followed by an aerobic dispensing process by fresh injection of oxygen as the bellows 7, 107 is used for generating dispensing pressure and relying on turbulent aeration of the brew being dispensed when the delivery tube 109 is corrugated.

The invention is not limited to the pressure relief valves, hand pump and non- return valves as described in the following example as any such pressurising device (such as a bottle of compressed gas) and any type of valve could be used equally well. The apparatus, as currently designed, is pressurised by the direct pumping of air into the flexible bag under pressure, but pressurisation could equally well be provided by injecting compressed air or other gas, such as C0₂ or N₂, from a pressured gas container, and pressurisation may be applied to the exterior of the flexible bag but inside the main rigid vessel 3. For example for US-style "mini-micro brewery" applications the apparatus may use injection of pressurised nitrogen and may have a cooling system in the delivery conduit.

Claims

C L A I M S

1. Brewing apparatus comprising a pressure-resistant vessel, a dispensing pump having an air outlet communicating with the interior of the vessel for pressurizing liquid in the vessel, and a pressure relief valve for venting excess dispensing pressure to lim it the dispensing pressure to a desired maximum value.

2. Apparatus according to claim 1 , and including a disposable liner within the pressure vessel and including a disposable delivery valve from the dispensing pump.

3. Apparatus according to either of claims 1 and 2, wherein said dispensing pump is a bellows pump.

4. Brewing apparatus comprising a pressure-resistant vessel, a flexible gas- and liquid-tight container having an opening for admission and discharge of liquid and being dimensioned to fit within the vessel to serve as a liner therefor, a closure for said opening in the liner, a discharge conduit adapted to have one end within the liner and the other end outside the vessel for communicating the interior of the liner with the exterior of the vessel, and flow control means to control dispensing flow of liquid by way of said discharge conduit, wherein the liner, and the closure for the liner are disposable after dispensing of the brewed liquid from within the liner.

5. Apparatus according to claim 4 wherein the discharge conduit is disposable.

6. Apparatus according to claim 4 or 5, wherein the closure includes a non-return valve for pressurizing air and the non-return valve is disposable with the closure.

7. Apparatus according to claim 4, 5 or 6 , wherein the flow control means comprise a pinch valve operable to pinch the discharge conduit for sealingly closing it during brewing and when liquid within the liner is not being dispensed.

8. Apparatus according to any one of claims 4 to 7, wherein the discharge conduit is a corrugated hose presenting internal ribbing around the hose.

9. Apparatus according to any one of claims 4 to 8, and including an air pump having a disposable one-way air delivery valve communicating with the interior of the liner, in the assembled configuration of the apparatus, and a one-way air inlet valve communicating with a gas space outside the liner.

10. Apparatus according to any one of the preceding claims wherein said pressure vessel is substantially spherical in shape.

11. Apparatus according to claim 10 and including outwardly projecting portions of said pressure vessel to define recesses in which fermentation sediment may preferentially settle.

12. Apparatus according to any one of the preceding claims, and including a pressure relief safety valve for allowing venting of the interior of the pressure vessel before a dangerous pressure level is reached.

13. Apparatus according to claims 7 and 12, wherein said pressure relief safety valve has a release pressure threshold higher than said dispensing pressure relief valve.

14. A method of brewing a fermentation beverage, comprising taking a vessel capable of withstanding the pressures arising during fermentation of the beverage, placing a disposable flexible liner within the vessel, covering the vessel with a cover plate to enclose the interior of the liner to avoid ingress of pollutants from outside the liner, inserting a dispensing tube sealingly through said cover plate and into the liner within said vessel, placing ingredients for brewing within said liner and maintaining it in a sealed condition during fermentation so as to allow anaerobic fermentation to take place, and after fermentation pressurizing the interior of said liner and allowing discharge of the fermented beverage, wherein, after completion of dispensing of the fermented beverage, the liner, and the cover plate, are disposed of and replaced by sterile fresh similar components before a next successive batch of the beverage is fermented.

15. A method according to claim 14, and including the step of disposing of the dispensing tube and replacing it by a fresh one before fermenting said next successive batch of the beverage.

16. A method according to claim 14 or 15, wherein said pres- surization is effective by way of an air pump to allow dispensing, and the discharge valve of said air pump is disposed of before the next successive batch is brewed.

17. A method according to claim 14, 15 or 16 wherein said cover plate includes a pressure relief valve for limiting dispensing pressure, and including the step of disposing of said cover plate and pressure relief valve at the end of dispensing one batch and before brewing a next successive batch.

18. A method according to claim 17, and including the step of re- pressurizing the interior of said liner intermittently when dispensing pressure drops, said pressure relief valve serving to limit the dispensing pressure to a desired value.

19. A method of brewing and dispensing a fermentation beverage, substantially as hereinbefore described with reference to the accompanying drawings.

20. Apparatus for brewing fermentation beverage substantially as hereinbefore described with reference to, and as illustrated in, Figures 1 to 13b, or Figure 14, of the accompanying drawings.