GB2123850A - A fermentation apparatus - Google Patents

Abstract

A fermentation apparatus includes a container (10) with a downwardly tapering internal cross section, which is used as both the fermentation vessel and a filtration vessel. A lower bulb (38) can be connected to and released from the lower end of the container, to receive the sediment during fermentation, and replaced by a filter unit (40) for filtration of the beverage, after termination of fermentation. The fermentation vessel has an inlet means (16) which is sealable and the vessel can be pressurised to increase the rate at which filtration occurs. <IMAGE>

Description

SPECIFICATION Fermentation apparatus and process This invention relates to a fermentation apparatus and process, and more particularly to a small scale apparatus for conducting fermentation to produce alcoholic beverages, e.g. beer and wines, and a process for use therewith.

Domestic production of fermented beverages, i.e. home wine and beer making, is an increasingly popular pastime. Its appeal is however in many instances limited by the need to acquire several different kinds of equipment and manipulate large volumes of liquid, e.g. in the transfer of the liquid from one vessel to another during the process, and the amount of space required for such apparatus and the conducting of such operations.

The production of carbonated fermented beverages on a domestic scale has often caused problems. For example, a common difficulty experienced in domestic beer-making is the obtaining of the correct degree of carbonation of the resultant product. It is normally attempted by including additional fermentable sugar in the beer bottles, to induce a secondary fermentation.

Either a flat beer or an excessively frothy beer, liable to burst its bottles, is produced all too frequently.

The practice of filtering fermented beverages prior to bottling thereof is becoming more popular on the domestic scale, as the benefits of careful filtration become more widely appreciated.

However, additional vessels and other equipment, and the transfer of large volumes of liquid, e.g. by syphoning, introduce risks of microbial contamination, oxidation and spoilage of the beverage.

The present invention provides a fermentation apparatus comprising a single container in which all process operations in making fermented beverages up to the bottling thereof are conducted. The vessel has a main container portion tapering in a downward direction to a relatively narrow, valved outlet conduit, to the lowermost end of which may be releasably secured a small volume bulb, or, in replacement thereof, a filter unit. The lower, small volume bulb may be used to collect the lees formed during fermentation, and to add ingredients to the fermenting liquor. When fermentation is complete, The bulb is replaced by the filter unit, through which the liquid is fed into storage containers.

Access to the interior of the container is provided through a valved top opening, to which a safety pressure relief valve may be fitted.

Thus according to one aspect of the present invention, there is provided a fermentation apparatus for production of alcoholic beverages and adapted for domestic use, comprising a container having a downwardly tapering internal cross-section, inlet means having a sealable closure therefor, outlet means at the bottom of said container, said outlet means including a valve which is movable between an open position and a closed position, a bottle residue receiving receptacle attachable to and releasable from the outlet means to be located downstream of the valve therein, said receptacle being of smaller volume than the container, a filter unit attachable to and releasable from the outlet means is replacement of said receptacle, said container being capable of being substantially hermetically sealed during the conduct of fermentation of liquid therein.

In a preferred form, the apparatus according to the invention has the shape of an inverted cone, with a circular horizontal cross-section, at its lower part. it is conveniently made of food grade plastic material, to permit ready cleaning and sterilization.

According to a second aspect of the present invention, there is provided a process of the production of alcoholic beverages, which comprises fermenting a fermentable liquid mixture in a container which has a downwardly tapering internal cross-section, a lowermost valved outlet, and a bottom residue receiving receptacle downstream of said outlet, collecting solid and semi-solid residues of said fermentation in said receptacle, closing said lowermost valved outlet and replacing said receptacle with a filter unit, opening said lowermost valve outlet and filtering the fermented liquid through the filter unit as it exits from the outlet from the container, and collecting the filtered, fermented liquid in a storage vessel.

The process of the present invention is a flat brewing or fermenting process, in which the fermentation is conducted at or slightly above atmospheric pressure. Preferably the apparatus includes, in its upper portion, a pressure relief valve, so that pressure therein is not permitted to exceed a predetermined and safe maximum, which is not far above atmospheric. This maximum pressure can be adjusted using the valve. A carbonated beverage can only be obtained directly by fermenting under pressure, under chilled conditions, which the domestic operator cannot reasonably do. Consequently, a flat beverage is produced which is filtered, and then bottled or put to similar storage. Any desired carbonation is performed as a separate step, after bottling, as described below.

Preferably also, the lower outlet means is removable from the container. The making of the lower section of the container in a conical shape, with the removable lower outlet means, also makes for ready cleaning and sterilization of the container after draining the contents therefrom, ready for re-use, and is particularly advantageous.

The container can be made in a wide variety of different sizes suitable for domestic use, e.g. one gallon-fifteen gallons. Normally one can expect to lose about one-half a litre of liquid during processing, from the preferred five gallon (twentyfive litre) size apparatus.

In the apparatus of the invention, it is preferred that the bottom residue receiving receptacle is in the form of a small-volume bulb, and has a volume of about one-tenth to one-fifth of the volume of the fermentation vessel. It provides a receptacle for receipt therein of sediment, lees etc., settling out of the beverage as fermentation proceeds. It may also be used to provide an initial air reservoir for aeration and rousing of the contents. In this method of operation, fermentation starts with the valve in the outlet closed and the bulb containing air. When the outlet is opened, air from the bulb bubbles upwardly through the fermenting liquid (wort) to aerate and rouse the liquid, often with beneficial effects on the yeast activity. The residues subsequently collected in the bulb can be discarded, or re-used as active yeast mixture to ferment the next batch.

Thus, in the process, the outlet means may be left in its open position during fermentation, with the lower, smaller container in position, so that fermentation is conducted under sealed conditions. The valved outlet means is closed to permit removal of the lower container when desired, and replacement thereof with the filter unit, whilst maintaining the seal on the beverage in the fermentation vessel.

In a preferred process according to the invention, for the making of beer, a filter aid is added to the liquid immediately prior to commencing the filtration. A suitable filter aid is finally divided diatomaceous earth, and may be used in quantities from about 5 grams to about 20 grams per gallon of fermented liquid. It is also preferred to pressurize the container whilst filtering, e.g. by pumping air or feeding carbon dioxide from a pressurized source into the air space above the liquid. Then the filtration takes placed rapidly (10--15 minutes for 5 gallons of liquid) and the filter aid does not have time to settle and cake.

The preferred filter medium for use in the present invention is cellulose in the form of filter paper. It is suitably contained in a replaceable cartridge unit, which can be releasably secured to the lowermost end of the outlet, in sealing fasion.

The paper therein is preferably arranged in fluted form, in a circular arrangement, with the feed of liquid to the outside of the circle. A most preferred filter paper is 5 micron filter paper. The use of the filter cartridge unit containing such a filter medium, in conjunction with the use of diatomaceous earth filter aid, leads to the formation of brilliantly clear beer in a total time of about seven days.

Also, the lower bulb can be used for addition to various substances to the fermenting liquid, such as clarifying agents. With the bottom outlet closed, the lower container can be removed, clarifying agent introduced into it, and then refitted. At the appropriate time, the valved outlet means is opened so that the liquid enters the lower container, and mixes with the contents of the lower container. Agitation may be undertaken, to assist in dispersion of the materials, e.g.

clarifying agent throughout the liquid in the apparatus. In winemaking, this suitably occurs when the fermentation is complete, so that the lower container is removed and cleaned of sludge residues prior to introduction thereto of the clarifying agent. Appropriate clarifying agents are well-known for wine and beer making, and include potassium sorbate, metabisulphite, ascorbic acid, isinglass, etc.

Thus in the process of the invention, all operations of fermentation, clarifying and filtering are conducted in a single vessel. The need for transferring, syphoning etc. the liquid is obviated.

As it issues from the vessel from the filter it is ready for bottling and optionally carbonation. Any desired carbonation is best performed in the bottle, supplying carbon dioxide from the cylinder thereof, through a valved pressure cap on the bottle.

A specific preferred embodiment of the invention is illustrated in the accompanying drawings, in which: Figure 1 is a diagrammatic perspective view of the apparatus; Figure 2 is a sectional view of a detail of the apparatus shown in Fig. 1; Figure 3 is a sectional view of filter unit, along the line 3-3 of Fig. 1; Figure 4 is a sectional view of a detail of the filter unit along the line 4-4 of Fig. 3.

In the drawings, like reference numerals indicate like parts.

The apparatus according to the invention as shown in Fig. 1 includes a container 10, the lower portion 12 of which is of inverted conical shape.

At its uppermost, part-spherical 14 there is a relatively large inlet 1 6 closed by a sealing, screw threaded closure 18. Two valves are provided in the inlet closure 18, the first of which 20 is a pressure relief safety valve and the second of which 21 is an inlet valve through which gases under pressure may be fed into the interior of the container. A stand is provided for the container 10, the stand having a pair of uprights 22, 24 between which the container 10 is suspended, and a base 26. The container 10 rests in a ring 28 which is pivotally supported in the stand uprights 22, 24 at the top end thereof. Thus the container may be simply lifted out of the ring 28 to remove it from the stand.When in position as illustrated, it can be pivoted in the vertical plane passing between the stand uprights 22, 24. This facilitates the placing of apparatus such as bottles etc. below the container 10, and manipulation of the lowermost end thereof, and in addition provides a means for agitating the contents in the container 10.

The lowermost end of the container 10 terminates in an outlet means in the form of a removable sleeve 30, threadabiy received on the screw threaded lowermost end 32 of the container (Fig. 2). The sleeve 30 has a manually operable closure valve 34. The lower end of sleeve 30 is internally screw-threaded at 36, for receiving, in sealing engagement therewith, either a small volume bulb 38 or a filter unit 40.

The filter unit 40 is stored in a receiving ring 42 attached to upright 24 of the stand. It includes an inlet hose 44 terminating in a screw threaded connector 46 which is threaded so as to be sealingly engagable with screw thread 36 at the bottom of sleeve 30 when required. The position of ring 42 and the length of inlet hose 44 are such that the filter unit can be sealingly connected to the bottom of sleeve 30 whilst it rests in its receiving ring 42.

The construction of filter unit 40 is shown in more detail in Figs. 3 and 4. It comprises a cap 48 threadably received in a main body 50, of cylindrical form. A filter cartridge 52 of generally cylindrical form is disposed verticaily within the main body 50 of the filter unit. The cartridge has upper and lower end members 54, 56 respectively, and an inner perforated cylindrical sleeve 58 defining an inner cylindrical cavity. The upper end member 54 is centrally apertured to provide communication between the inner cylindrical cavity and an outlet conduit 60 passing right angularly through the cap 48 and communicating with outlet hose 62. An upstanding projection 64 on the centre of the bottom in the wall of main body 50 is received within a recess in the lower end member 56, to locate the cartridge 52.A generally cylindrical fluted filter paper 66, of five micron size, is received within formations on end members 54, 56 to provide the filter medium. Inlet hose 44 communicates via inlet conduit 68 in the cap 48 with the main body 50 exteriorly of the cartridge 52.

The upright 22 of the stand is provided with integral holding formation 70, in which is received a standard, pressurized cylinder 72 of carbon dioxide. As indicated in broken lines on Fig. 1, the outlet 74 from cylinder 72 is connectable either to inlet valve 21 to pressurize the interior of container 10 or to storage bottle 76 via valved cap 78 thereof for carbonating bottled beverage.

Additional receiving formations 80 are provided on the stand, for storage of bottles 76 thereon if desired.

In a process according to the invention, for making beer, intially closure 18 is removed and closure 34 is closed, and then the fermentation ingredients (malt, sugar, hops, water, yeast nutrients, etc.) are added to the container 1 0. The ingredients are thoroughly mixed therein, yeast is added, and the closure 1 8 fitted in place, with the safety valve 20 closed but preset to open at a predetermined, safe maximum pressure. Bulb 38 is fitted into place, in sealing engagement, and then valve 34 is opened. Air from bulb 38 bubbles through the liquid wort in container 12, rousing and aerating the ingredients, and liquid enters the bulb 38. Fermentation then proceeds, with deposit of lees, solid residues etc. into bulb 38.If carbon dioxide is generated in such large quantities at the pressure setting of safety valve 20 is exceeded, pressure is relieved by discharging gas therethrough. When fermentation is complete (5-7 days), valve 34 is closed and bulb 38 and its contents are removed.

Next, filter unit 40 is connected to the container 10, by fitting connector 46 to the screw threaded end 36 of sleeve 30 in sealing fashion.

Closure 1 8 is removed and diatomaceous earth filter aid, in the approximate amount of 50 grams per 5 gallons of liquid, is added to the contents.

Closure 1 8 is replaced, with the safety valve 20 appropriately set (about 25 psi). Promptly after addition of the filter aid an dispersion thereof in the liquid, valve 34 is opened, cylinder 72 is connected to inlet valve 21, and the liquid is filtered through filter unit 40 under carbon dioxide pressure. in this manner, 5 gallons of fermented liquid beverage can be filtered in a time period of approximately 10-1 5 minutes. Brilliantly clear fermented beverage is obtained through outlet hose 62, fed into bottle 76 which may subsequently be carbonated from cylinder 72 to provide sparkling alcoholic beverage.

Claims (15)

Claims

1. Fermentation apparatus for production of alcoholic beverages and adapted for domestic use, comprising: a container having a downwardly tapering internal cross-section; inlet means having a sealable closure therefore, outlet means at the bottom of said container, said outlet means including a valve which is movable between an open position and a closed position; a bottom residue receiving receptacle attachable to and releasable from the outlet means to be located downstream of the valve therein, said receptacle being of smaller volume than the container; a filter unit attachable to and releasable from the outlet means in replacement of said receptacle; said container being capable of being substantially hermetically sealed during the conduct of fermentation of liquid therein.

2. Apparatus according to claim 1 wherein the container is of inverted conical shape, with circular horizontal cross-section.

3. Apparatus according to claim 1 or claim 2 including a safety pressure release valve in the upper part of the container, preset to withstand a predetermined pressure within the container.

4. Apparatus according to claim 3 wherein said release valve is disposed in the sealable closure for the inlet means.

5. Apparatus according to any preceding claim wherein said outlet means is manually removable from the bottom of said container to facilitate emptying and cleaning thereof.

6. Apparatus according to any preceding claim wherein said filter unit contains a paper filter medium, arranged in generally cylindrical fluted form, for liquid to pass from the periphery to the centre thereof on filtration therethrough.

7. Apparatus according to any preceding claim also including a supporting stand in which the container is releasably supported for pivoting movement in one vertical plane.

8. Apparatus according to claim 7 wherein said supporting stand includes holding means for receiving the filter unit when not in use, holding means for receiving the bottom residue receiving receptacle when not in use, and storage container receiving means.

9. Apparatus according to any preceding claim further including, in its upper portion thereof, a valve by means of which additional gas may be fed to the upper interior space within the container, for increasing the pressure on liquid contents therein.

1 0. A process for the production for alcoholic beverages, which comprises fermenting a fermentable liquid mixture in a container which has a downwardly tapering internal cross-section, a lowermost valved outlet, and a bottom residue receiving receptacle downstream of said outlet and removable from engagement therewith, collecting solid and semi-solid residues of said fermentation in said receptacle as fermentation proceeds, closing said lowermost valved outlet and replacing said receptacle with a filter unit, opening said lowermost valved outlet and filtering the fermented liquid through the filter unit as it exits from the outlet from the container, and collecting the filtered, fermented liquid in a storage vessel.

11. A process according to claim 10 which is conducted at room temperature.

12. A process according to claim 10 or claim 11 which includes the additional step of pressurizing the upper part of said fermentation vessel with air or carbon dioxide, after fitting said filter unit, to assist in urging the liquid through the filter unit.

13. A process according to any of claims 10 to 12, including the additional step of adding a solid, finely divided filtering aid to the fermented liquid immediately prior to filtration thereof.

14. A process according to claim 13 wherein said filtering aid is diatomaceous earth.

15. A process of any of claims 10 to 14 including a final step of carbonation of the fermented beverage after filtration.

1 6. Fermentation apparatus for production of alcoholic beverages and adapted for domestic use as claimed in claim 1, substantially as described herein with reference to the accompanying drawings.

1 7. A process for the production of alcoholic beverages according to claim 10, substantially as herein described.