GB2140821A

GB2140821A - Fermentation of sugar solutions

Info

Publication number: GB2140821A
Application number: GB08411540A
Authority: GB
Inventors: Edward East
Original assignee: EDME Ltd
Current assignee: EDME Ltd
Priority date: 1983-05-12
Filing date: 1984-05-04
Publication date: 1984-12-05
Also published as: GB8411540D0

Abstract

A process for removing flavour and colour from a fermented sugar solution comprises adding one or more substances e.g. an alkali and carbon to the solution which will react or otherwise combine with unpalatable flavour and unwanted colour to produce a soluble inoffensive product and/or an insoluble product which can be separated from the solution.

Description

SPECIFICATION Fermentation of sugar solutions This invention relates to the production of ethyl alcohol by fermentation.

Fermentation of sugar solutions to produce ethyl alcohol is always accompanied by the production of by-products generally organic acids, higher alcohols, esters and ketones which impart flavour and/or colour to the fermented liquor. These flavours are in many cases extremely unpalatable, and they are often so pronounced that they are always detectable even when another flavouring is added. Even the most simple sugars such as glucose and sucrose will, on fermentation produce unpleasant flavours. In addition to the flavours of the by-products ethyl alcohol solutions produced by natural fermentation almost always have a residual yeast flavour from the yeast cells and products of yeast autolysis.

In order to remove undesirable flavours and colours it has been the practice to distill the fermented sugars. However, distillation by the "home brewer" of fermented sugars is prohibited by statute. It is, therefore, very difficult for individuals to produce a bland alcohol solution to which they may add a flavouring in order to simulate well known distilled spirits and liqueurs such as gin, whiskey, brandy and the like.

The present invention has been made from a consideration of this problem.

According to the invention there is provided a process for at least partial removal of flavour and/or colour from a fermented sugar solution comprising adding to the solution one or more substances that will react or otherwise combine with unpalatable flavour and/or colouring material in said solution to produce a soluble inoffensive product and/or an insoluble product which can be separated from the solution.

By the invention, therefore, undesirable byproducts can be selectively removed without recourse to unlawful distillation. A bland alcohol solution can be obtained which can be used as a base to which palatable flavourings and colours can be added as desired.

The substances to be added to the fermented sugar solution are chosen having regard to the products to be removed. An alkali may be added to neutralise acid by-products.

Preferably the alkali chosen is one that is insoluble so that any surplus can be removed for example by filtration. Useful alkalis are calcium carbonate and magnesium carbonate.

Higher alcohols, esters and ketones can be removed by the addition of activated carbon and subsequent separation of solids from the solution, for example by filtration. The activated carbon will also remove undesirable colours from the solution.

Yeast debris can be removed with the use filter aid such as kieselguhr, perlite, silica hydrogel, aluminium oxide, bentonite and the like. The filter aid is preferably added to the solution after any insoluble substances have been allowed to settle out and been separated for example by siphoning, decanting or the like.

If desired the additive substances can be introduced to the solution together or separately. In one embodiment of the invention the additive substances are added separately and any precipitate filtered or otherwise removed between each addition and if necessary at the end of the treatment. Adjustment of the amount of additive, or omission altogether can be adopted in order to preserve in the solution any flavour and/or colour that is wanted. In most cases from 5-10 grammes of alkali and from 8-12 grammes carbon per gallon (4.5 litres) of solution is adequate. If the carbon is low grade then a greater amount may be required. In addition from 5-20 grammes of filter aid per gallon of solution is generally appropriate.

The invention also provides a composition for removal of unwanted flavour and/or colour in fermented sugar solutions, comprising an alkali, carbon and/or a filter aid for addition to a fermented sugar solution.

The following Example further illustrates the invention.

EXAMPLE Glucose (300 g) and Sucrose (300 g) were dissolved in hot water (600 ml). Cold water was added (1000 ml) to give a temperature of 25"g: and a gravity of 1.11. Dried yeast (15 g) was added and the mixture was fermented in a plastic container at approximately 24"C for 1 7 days. The gravity was reduced to 0.985. The bulk of the liquid was decanted from the yeast which collected at the bottom of the container. The cloudy liquid so produced was slightly coloured and tasted very fruity and acid.

Calcium carbonate (5 g), activated carbon (5 g) and kieselguhr (10 g) were added to the liquid and the mixture was shaken and left to stand for 24 hours with occasional shaking.

The mixture was then filtered through a filter paper. The resulting liquid was colourless and tasted bland.

1. A process for at least partial removal of flavour and/or colour from a fermented sugar solution comprising adding to the solution one or more substances that will react or otherwise combine with unpalatable flavour and/or colouring material in said solution to produce a soluble palatable product and/or an insoluble product which can be separated from the solution.

2. A process as claimed in Claim 1 wherein the substances added to the' fer

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Fermentation of sugar solutions This invention relates to the production of ethyl alcohol by fermentation. Fermentation of sugar solutions to produce ethyl alcohol is always accompanied by the production of by-products generally organic acids, higher alcohols, esters and ketones which impart flavour and/or colour to the fermented liquor. These flavours are in many cases extremely unpalatable, and they are often so pronounced that they are always detectable even when another flavouring is added. Even the most simple sugars such as glucose and sucrose will, on fermentation produce unpleasant flavours. In addition to the flavours of the by-products ethyl alcohol solutions produced by natural fermentation almost always have a residual yeast flavour from the yeast cells and products of yeast autolysis. In order to remove undesirable flavours and colours it has been the practice to distill the fermented sugars. However, distillation by the "home brewer" of fermented sugars is prohibited by statute. It is, therefore, very difficult for individuals to produce a bland alcohol solution to which they may add a flavouring in order to simulate well known distilled spirits and liqueurs such as gin, whiskey, brandy and the like. The present invention has been made from a consideration of this problem. According to the invention there is provided a process for at least partial removal of flavour and/or colour from a fermented sugar solution comprising adding to the solution one or more substances that will react or otherwise combine with unpalatable flavour and/or colouring material in said solution to produce a soluble inoffensive product and/or an insoluble product which can be separated from the solution. By the invention, therefore, undesirable byproducts can be selectively removed without recourse to unlawful distillation. A bland alcohol solution can be obtained which can be used as a base to which palatable flavourings and colours can be added as desired. The substances to be added to the fermented sugar solution are chosen having regard to the products to be removed. An alkali may be added to neutralise acid by-products. Preferably the alkali chosen is one that is insoluble so that any surplus can be removed for example by filtration. Useful alkalis are calcium carbonate and magnesium carbonate. Higher alcohols, esters and ketones can be removed by the addition of activated carbon and subsequent separation of solids from the solution, for example by filtration. The activated carbon will also remove undesirable colours from the solution. Yeast debris can be removed with the use filter aid such as kieselguhr, perlite, silica hydrogel, aluminium oxide, bentonite and the like. The filter aid is preferably added to the solution after any insoluble substances have been allowed to settle out and been separated for example by siphoning, decanting or the like. If desired the additive substances can be introduced to the solution together or separately. In one embodiment of the invention the additive substances are added separately and any precipitate filtered or otherwise removed between each addition and if necessary at the end of the treatment. Adjustment of the amount of additive, or omission altogether can be adopted in order to preserve in the solution any flavour and/or colour that is wanted. In most cases from 5-10 grammes of alkali and from 8-12 grammes carbon per gallon (4.5 litres) of solution is adequate. If the carbon is low grade then a greater amount may be required. In addition from 5-20 grammes of filter aid per gallon of solution is generally appropriate. The invention also provides a composition for removal of unwanted flavour and/or colour in fermented sugar solutions, comprising an alkali, carbon and/or a filter aid for addition to a fermented sugar solution. The following Example further illustrates the invention. EXAMPLE Glucose (300 g) and Sucrose (300 g) were dissolved in hot water (600 ml). Cold water was added (1000 ml) to give a temperature of 25"g: and a gravity of 1.11. Dried yeast (15 g) was added and the mixture was fermented in a plastic container at approximately 24"C for 1 7 days. The gravity was reduced to 0.985. The bulk of the liquid was decanted from the yeast which collected at the bottom of the container. The cloudy liquid so produced was slightly coloured and tasted very fruity and acid. Calcium carbonate (5 g), activated carbon (5 g) and kieselguhr (10 g) were added to the liquid and the mixture was shaken and left to stand for 24 hours with occasional shaking. The mixture was then filtered through a filter paper. The resulting liquid was colourless and tasted bland. CLAIMS

2. A process as claimed in Claim 1 wherein the substances added to the' fer mented sugar solution comprise an alkali, carbon and a filter aid.

3. A process as claimed in Claim 2, wherein the alkali is calcium carbonate or magnesium carbonate.

4. A process as claimed in Clairn 2 or Claim 3, wherein the filter aid is keiselguhr, perlite, silica hydrogel, aluminium oxide or bentonite.

5. A process as claimed in any preceding claim wherein the substances are added together to the solution.

6. A process as claimed in any of Claims 1 to 4 wherein the substances are added separately to the solution.

7. A process as claimed in Claim 6 wherein any precipitate is removed after the addition of a substance to the solution prior to the addition of any further substance.

8. A process for at least partial removal of flavour and/or colour from 2 fermented sugar solution substantially as described herein with reference to the Example.

9. A fermented sugar solution treated by the process as claimed in any preceding claim.

10. A composition for use in the process as claimed in any of Claims 1 to 8 comprising an alkali, carbon and a filter aid.