GB2157314A

GB2157314A - Home brewing system

Info

Publication number: GB2157314A
Application number: GB08509010A
Authority: GB
Inventors: John Valentine Cross
Original assignee: Individual
Current assignee: Individual
Priority date: 1984-04-10
Filing date: 1985-04-09
Publication date: 1985-10-23
Also published as: GB8409238D0; AU4099385A; GB8509010D0

Abstract

The system for the home brewing of beer or wine consists of preparing a yeast fermentable substrate syrup such as a high maltose syrup with a specified sugar spectrum. To this may be added protein, amino acids, and yeast nutrients. The ingredient-balanced syrup is sterilized and aseptically packaged. The user empties the sugar solution into a container and adds potable water at fermentation temperature to dilute the substrate. Yeast is added and the container is sealed and placed under a water seal. The container is preferably collapsable. After fermentation, the water seal is removed and the container is closed or sealed and can be used to dispense the beverage once settling has taken place, the collapsability of the container preventing or eliminating the necessity of air entry to replace the liquid withdrawn. This process eliminates the usual boiling of the wort and subsequent cooling period to reach fermentation temperature.

Description

SPECIFICATION Home brewing system BACKGROUND OF THE INVENTION This invention relates to new and useful improvements in the process of brewing beer and/or wine, particularly the brewing process as carried out in what might be termed noncommercial locations such as homes and the like.

As the price of commercial beer has increased it appears the barrier for "impulse" or "no decision" purchases has been passed for some segments of the purchasing public. This is perhaps one of the explanations of levelling off of total market volume for beer in Canada and elsewhere, in recent years.

Under these circumstances kits for producing beer on a home scale become more appealing and there has been a substantial increase in the number and type of home brew kits offered for sale at the retail level. But on closer examination the use of these kits is less convenient and attractive than it first appears.

The system essentially involves preparing a fermentable substrate, or wort, by a process of boiling an aqueous solution of malt extract with added sucrose and/or glucose, cooling, transferring to another container for fermentation, and cellar conditioning, and filtering prior to bottling and capping. Although this system may be economical based on cost inputs alone, the labor required and the inconvenience of the process make the system appealing only to the avid hobbyist. Further, the complexities of the process provide several opportunities for error and spoiled or unsatisfactory brews can frequently result.

SUMMARY OF THE INVENTION The challenge in producing a high quality home brew product is to assemble a series of materials and processes which are reproducibly reliable.

Beer is the end result of yeast fermentation of a nutrient sugar solution known as wort.

Traditionally, wort is prepared from a mash of barley-malt, with or without additional carbohydrate adjunct, to give a desired spectrum of sugars for optimum process efficiency and beer quality. Glucose, fructose, sucrose, maltose and maltotriose represent the set of fermentable sugars in brewers' wort, of which maltose is the most abundant.

The ratio of the individual fermentable sugars is extremely important to the character of the fermentation and the organoleptic properties of the resultant beer. For example, when the combined concentration of glucose, fructose and sucrose exceeds approximately 20% of the total fermentable sugars in the wort, the fermentation becomes slow, often incomplete, and produces a beer of inferior quality and flavour. The influence of the above mentioned sugars on the yeast metabolism is known as the "glucose effect".

By way of explanation of the "glucose effect", sugars such as glucose, fructose and sucrose can cross the yeast cell-membrane without the expenditure of cellular energy; on the other hand maltose and maltotriose require the mediation of appropriate yeast permeaser to "pump" maltose and maltotriose across the cell membrane. Yeast cells grown in the presence of excessive concentrations of glucose, fructose and sucrose do not possess a vigorous permease system due to metabolic represssion. Thus when the more assimilable sugars such as glucose, fructose and sucrose are exhausted during the fermentation, the yeast cells do not possess a sufficiently active permease system to transport maltose and maltotriose satisfactorily. Hence the metabolic phenomenon known as the "glucose effect".

Home-brew kits currently on the market require the addition of a significant quantity of sucrose and/or glucose to supplement the sugars in the malt-extract. The addition of these sugars to the wort induces, to a lesser or greater extent, the undesirable "glucose effect" during the subsequent fermentation.

If the combined level of glucose, fructose and sucrose in the fermentation wort is greater than about 15% of the total carbohydrate in the wort, the fermentation will proceed, albeit somewhat sluggishly, and will tend to favour the production of fusel oils and other compounds which result in a beer with a very undesirable "ester" or "varnish" type character. To overcome these negative effects, in the present invention the combined level of glucose, fructose and sucrose in the fermentation wort is preferably less than 15% by weight of the total carbohydrate, thus resulting in the production, in a reproducible manner, of a desirable, high quality product by the procedure proposed.

In addition to the glucose, fructose and sucrose, the wort preferably contains in the range of 50-55% of maltose, measured as a percentage of the total carbohydrate in the wort, and maltotriose in the range of 5-10%, so that the total fermentable sugars is preferably in the range of 75% of the total carbohydrates in the wort. The balance of the carbohydrates are maltotretrose and other higher sugars.

Recent developments in biotechnology of the corn syrup industry permit the formulation of a superior home-brew system which is inexpensive, convenient and essentially foolproof. Concentrated sugar solutions can be made with any desired blend or mixture of different sugars. Thus a syrup can be "tailor made" with a specified carbohydrate spectrum to match that in the classical brewers' wort and can be used very effectively as a basis for a home-brew system. Such a high maltose syrup with a specified sugar spectrum is supplemented with protein, amino acids and yeast nutrients, sufficient in type and quality to support the fermentation and contribute to the flavour of the resultant beer.

Preferentially, the addition of an appropriate quantity of malt extract or brewers' wort made from 100% barley-malt would provide the relevant yeast nutritional and flavour substances. However, the use of such malt-derived materials should not be construed as limiting in any way.

The ingredient-balanced syrup is sterilized and aseptically packaged into a suitable container such as the plastic "pillows" used to package milk, and can thereafter be sold or retailed without the necessity of refrigeration for an extended shelf-life period of several months.

Once purchased, the home-brew procedure is as follows. The consumer empties the sugar solution into a suitable container such as a cube-shaped plastic container similar to the collapsible plastic containers used by campers for water. The container must, of course, be thoroughly clean and essentially sterile. Potable water at fermentation temperature is now added to the container to dilute the yeast fermentable substrate to a predetermined specific gravity. For example, one volume of a 37 degree Baume syrup diluted with six volumes of water would produce a beer with an alcohol concentration similar to that found in commercially produced beers. Water obtained from a domestic tap contains sufficient dissolved oxygen to support the subsequent fermentation.

Unlike the established procedures for the standard home-brew kits, the wort does not have to be boiled, thus eliminating the "kettle" operation and the subsequent cooling period to reach fermentation temperature. A prepared amount of special brewers' yeast is now added and if desired, hop extract, color and/or additional flavouring materials may be added at this time. The container is then sealed with the screw-on spigot. The container is agitated to mix the contents and placed, with the spigot on the top, in a cool location.

A conventional water seal (a double "U" shaped glass or plastic tube) is attached to the spigot outlet and the spigot is opened. Other types of collapsible containers may, of course, be used as long as the operational characteristics are retained.

The fermentation now proceeds in a normal manner. The seal permits carbon dioxide to escape as it is evolved, while at the same time preventing the entry of air. Thus the fermentation proceeds in a controlled environment.

After a period of 5-7 days, when the fermentation subsides, the spigot is closed and the seal is removed. The cubic container is now turned so that the spigot is on the bottom and the container placed in a location from which the beer will subsequently be drawn. The yeast strain used is specifically selected for its flocculating characteristics in the end-fermentation phase and settles, over a period of several days, to the bottom of the container below the spigot line. The degree of flocculation is critical so that after the yeast settles, the beer is clean, clear and appealing in appearance and taste. Refrigeration during this portion of the process, may facilitate and improve the settling and clarification. During this settling phase, the carbon dioxide given off from the residual declining fermentation will be captured in the container to give carbonation to the beer.

The beer is then drawn off from the spigot with the container collapsing and with air being excluded so that the product can be maintained in an acceptable condition for some considerable time. When emptying the container is thoroughly washed, sanitized with a suitable agent such as a sulphite solution, and used repeatedly through the same process.

This basic process can accommodate several modifications to produce a variety of beers. For example, when fermentation phase has ended, different hop extracts, or coloring agents, or flavouring agents such as ginger or fruit flavours may be added to enable the consumer to modify the product to individual preferences.

The relatively simple nature of this process and the opportunity for tight quality control of prepackaged ingredients should ensure a high success rate for home brewers.

An important dimension to the commercial development of this product is the selection of the flocculating yeast strain. Yeast strains with the appropriate flocculating characteristics may be screened from those available in national culture collections. The yeast or yeasts which are used are critically important to ensure the repeated production of a good quality beer. The yeast strain or strains used must be suitable for brewing and must be well known and well demonstrated to consistently produce a beer of high quality. Many brewing yeasts can produce a good beer, but a strain or strains are used which produce a better beer under the terms of this invention.

In addition to these excellent brewing characteristics the yeast must have a self-flocculating character so that as the fermentation subsides and completes, the yeast settles effectively so leaving a relatively clear supernatant. Yeasts which may be used include, but are not limited to, appropriate brewing strains of Saccharomyces cerevisiae and Saccharomyces carlsbergensis which possess the aforementioned characteristics.

Similarly, when this invention is used for the production of wines, or other beverages such as "pop wine", to which it is so readily applicable, the yeast must be selected from a recognized class of wine yeasts and be a well demonstrated producer of excellent quality wines. In addition of course, the wine yeast or yeasts must possess the self-flocculating characteristics described earlier.

The technology to produce the required sugar syrup is commercially available, and all the other process components, such as yeast nutrients added for yeast growth and fermentation vigor, may need refinement as the process details and fermentation parameters are established. It will also be appreciated that the various components can be tailored to suit different marketing needs not only nationally but internationally.

Although the process described above relates to the home brewing of beer, it will be appreciated that it may readily be adapted to home-wine making by using appropriate must, syrup and wine-yeast to effect the fermentation. Specific finishing and clarifying agents may be incorporated as necessary.

The particular appeal of this invention is its inherent process integrity, ease of application and cost effectiveness. The components may come from several industrial sectors and all could be supplied from national sources. The product has international market potential and may be tailor-made for different market needs in different countries. Both the product, the various components, and the technology behind the product, may be sold on international markets.

Since various modifications can be made in my invention as hereinabove described, and many apparently widely different embodiments of same made within the spirit and scope of the claims without departing from such spirit and scope, it is intended that all matter contained in the accompanying specification shall be interpreted as illustrative only and not in a limiting sense.

Claims

1. A process for the non-commercial brewing of beer or wine consisting of the steps of: (a) preparing a yeast-fermentable substrate syrup; (b) aseptically packaging same including sterilization of the substrate syrup and the packaging therefore; (c) placing said substrate in a sterilized, flexible container having a spigot adjacent one end thereof; (d) adding sufficient potable water at fermentation temperature to said container to produce, after fermentation, a desired alcoholic content to the mixture; (e) adding a suitable yeast to said container, said yeast having good flocculating characteristics particularly at the end-fermentation phase; (f) sealing said container with a water seal at said spigot at the upper side thereof, said spigot being adjacent the upper end of said container; (g) fermenting the contents of the container in a suitable environment;; (h) removing said water seal and closing said container when fermentation has been effectively completed; (i) reversing said container whereby said spigot is adjacent the base thereof and above the flocculent level; (j) withdrawing the flocculent free liquid via said spigot.

2. The process according to claim 1 in which said yeast-fermentable substrate syrup includes a combination of glucose, fructose and sucrose constitutes less than 15% by weight of the total carbohydrate, 50-55% by weight of maltose and between 5-10% of maltotriose whereby the total fermentable sugars constitutes approximately 75% by weight of the total carbohydrate in the syrup, the balance of the carbohydrates comprising maltotetrose and other higher sugars.

3. The process according to claim 1 in which the yeast is self-flocculating and is selected from the brewing strains consisting of Saccharomyces cerevisiae and Saccharomyces carlsbergensis.

4. The process according to claim 2 in which the yeast is self-flocculating and is selected from the brewing strains consisting of Saccharomyces cerevisiae and Saccharomyces carlsbergensis.

5. The process according to claim 1 which includes the addition of protein, amino acids and yeast nutrients.

6. The process according to claim 2 which includes the addition of suitable coloring and flavouring materials.

7. A process for the non-commercial brewing of beer consisting of the steps of: (a) preparing a yeast-fermentable substrate syrup and sterilizing same; (b) packaging same aseptically; (c) mixing said substrate is a sterilized, flexible container with sufficient potable water at fermentation temperature to produce, after fermentation, a beer having the desired alcoholic content; (d) adding a suitable brewers yeast to said container, said yeast having good flocculating characteristics particularly at the end-fermentation phase; (e) sealing said container with a water seal; (f) fermenting the contents of the container in a suitable environment;; (g) removing said water seal and closing said container, said container including a spigot adjacent the base thereof and situated above the level of the flocculent whereby clear beer may be dispensed from the flexible package without the intake of the air occurring.

8. The process according to claim 7 in which said yeast-fermentable substrate syrup includes a combination of glucose, fructose and sucrose constitutes less than 1 5% by weight of the total carbohydrate, 50-55% by weight of maltose and between 5-10% of maltotriose whereby the total fermentable sugars constitutes approximately 75% by weight of the total carbohydrate in the syrup, the balance of the carbohydrates comprising maltotetrose and other higher sugars.

9. The process according to claim 7 in which the yeast is self-flocculating and is selected from the brewing strains consisting of Saccharomyces cerevisiae and Saccharomyces carlsbergensis.

10. The process according to claims 8 in which the yeast is self-flocculating and is selected from the brewing strains consisting of Saccharomyces cerevisiae and Saccharomyces carlsbergensis.

11. The process according to claim 7 which includes the addition of protein, amino acids and yeast nutrients.

12. The process according to claim 7 which includes the addition of suitable coloring and flavouring materials.

1 3. A kit for home brewing comprising in combination a sterile, closed, flexible container, a yeast-fermentable substrate syrup therein, and a fermenting yeast for said syrup.

14. The kit according to claim 1 3 in which said yeast-fermentable syrup includes a combination of glucose, fructose and sucrose constituting less than 15% by weight of the total carbohydrate, 50-55% by weight of maltose and between 5-10% of maltotriose whereby the total fermentable sugars constitutes approximately 75% by weight of the total carbohydrate in the syrup, the balance of the carbohydrates comprising maltotetrose and other higher sugars.

1 5. The kit according to claim 1 3 in which said yeast is self-flocculating and is selected from the brewing strains consisting of Saccharomyces cerevisiae and Saccharomyces carlsbergensis.

16. The kit according to claim 14 in which said yeast is self-flocculating and is selected from the brewing strains consiting of Saccharomyces cerevisiae and Saccharomyces carlsbergensis.

1 7. A yeast-fermentable substrate syrup which includes a combination of glucose, fructose and sucrose constitutes less than 15% by weight of the total carbohydrate, 50-55% by weight of maltose and between 5-10% of maltotriose whereby the total fermentable sugars constitutes approximately 75% by weight of the total carbohydrate in the syrup, the balance of the carbohydrates comprising maltotetrose and other higher sugars.

18. A yeast for brewing which is selfflocculating and is selected from the brewing strains consisting of Saccharomyces cerevisiae and Saccharomyces carlsbergensis.