Process for Preparing a Malt-Based Beverage

Abstract

A process of preparing a malt-based beverage includes a method having the following steps. Fermenting a wort to obtain a fermented malt-based beverage to achieve an original extract level A in a range of 10 PI-20 PI is performed. Then, concentrating the fermented malt-based beverage by removal of water therefrom to obtain a concentrated malt-based beverage occurs. The concentrated malt-based beverage is diluted for consumption by addition of water or a water based diluent to an extract level B higher than A.

Claims

1. A process of preparing a malt-based beverage, said method comprises the steps of: fermenting a wort to obtain a fermented malt-based beverage to achieve a original extract level A in a range of 10 PI-25 PI; concentrating said fermented malt-based beverage by removal of water therefrom to obtain a concentrated malt-based beverage; wherein the concentrated malt-based beverage is diluted for consumption by addition of water or a water based diluent to an original extract level B higher than A.

2. The process according to claim 1, the wort fermented to achieve a real degree of fermentation of 65 to 90%, preferably of 70 to 80%.

3. The process according to claim 1, the concentration step comprising one or more of freeze concentration, concentration by reverse osmosis, nanofiltration, ultrafiltration or distillation.

4. The process according to claim 1, the concentration step comprising a first step of nanofiltration, obtaining a concentrated extract fraction and a permeate and subsequently a concentration step of the permeate to selectively remove water therefrom.

5. The process according to claim 1, the ratio of B/A is in the range of 1.25 to 2.5.

6. The process according to claim 1, the concentration step concerning a concentration of the beverage solids by a factor of at least 3, preferably at least 4, and most preferably at least 6 in view of the fermented malt-based beverage prior to concentration.

7. The process according to claim 1, comprising selecting the amount of water for dilution of the concentrated malt-based beverage to obtain a beverage having an original extract level in a range of 8 PI-18 PI.

8. The process according to claim 2, the ratio of B/A is in the range of 1.25 to 2.5.

9. The process according to claim 3, the ratio of B/A is in the range of 1.25 to 2.5.

10. The process according to claim 4, the ratio of B/A is in the range of 1.25 to 2.5.

Description

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

[0019] The present invention concerns a process of preparing a malt-based beverage, the process comprising the steps of brewing a wort, preferably based on malt-based mash, boiling said wort and subsequently fermenting the wort. After fermentation the fermented broth is filtered and subsequently stabilized (eg with PVPP or kieselguhr) to obtain the fermented beverage.

[0020] The fermented beverage has a original extract level of between 10 Plato and 25 Plato.

[0021] Following the stabilisation, the fermented beverage is concentrated, i.e. water is removed from the beverage, thereby concentrating the maltotetraose in the beverage for for example at least 3 times, preferably at least 4 times or even up to 6 times or more in comparison with the fermented beverage after stabilisation.

[0022] During the concentration step a fraction of the some flavour components in the beverage will be removed together with the water. Such removal during concentration, thereby altering the signature of the malt-based beverage. This post-fermentation and stabilization removal of components allows for tweaking the brewing and fermentation of the malt-based beverage to allow a more cost-efficient brewing and fermentation process. As an example, adjusting the amount of dimethylsuflide (DMS) in the fermented beverage, by allowing selective removal of DMS together with water during for example a nanofiltration step allows reducing the boiling time of the wort, as in brewing of regular beer, DMS is removed during boiling and the boiling of the wort will only be stopped once the DMS levels are below a given threshold value. Experiments have shown that with nanofiltration, the DMS level in the beer can be reduced with about 91% for Stella Artois and with about 83% for Leffe, whilst with a concentration step comprising freeze concentration the DMS levels can be reduced by about 27% (weight %) for Stella Artois and about 15% for Leffe.

[0023] According to another example, the fermentation conditions can be altered by applying more stress on the yeast (less stringent temperature conditions during fermentation), resulting in a malt-based beverage having a higher concentration of esters such as eg. ethylformate, n-amyl acetate, isoamyl acetate, isobutyl propionate, methyl butyrare, ethyl butyrate, n-butyl butyrate, n-amyl butyrate, isoamyl valerate, methyl salicylate and/or combinations thereof. During the total weight amount of eg isoamylacetate can be lowered by 15% (weight %) for Stella Artois when using freeze concentration and even up to 60% (weight %) with nanofiltration, whilst for Leffe, the isoamylacetate can be lowered by 11% by freeze concentration and by 60% with nanofiltration.

[0024] The amount of maltotetraose is not or only in a very limited amount affected by the concentration of the malt-based beverage. As such the ratio A/B is adjusted during concentration to a level X.sub.final lower than X.sub.1.

[0025] After concentration the malt-based beverage is preferably packed in packaging providing adequate gas and light barrier properties. And for consumption, the malt based beverage concentrate is preferably rediluted, either with water or another liquid (alcohol, beer, cider, . . . ) to obtain a malt-based beverage having a original extract level of the final malt based beverage preferably ranging between 8 Plato and 20 Plato. The amount of diluent is hereby prefarably chosen to be slightly lower than the amount of water removed during concentration. Due to the addition of less water than originally removed, the loss of some flavour components in the beverage (beer) will be limited, thereby allowing achieving a beverage signature close to that of the beverage as brewed.

[0026] The diluent may optionally have CO.sub.2, N.sub.2 or N.sub.2O dissolved therein.

[0027] The method of concentration of the fermented malt-based beverage is preferably one or more of freeze concentration, concentration by reverse osmosis, nanofiltration, ultrafiltration or distillation.

[0028] A preferred method for obtaining a concentration level of 3, preferably 4, most preferably 6 or more concerns a 2-step concentration method, said method comprising the steps of:

[0029] a) Subjecting beer or cider to a first concentration step comprising nanofiltration or reverse osmosis to obtain a retentate and a fraction comprising alcohol and volatile flavour components, wherein the retentate is characterised by the concentration of unfilterable compounds equal to or higher than 20% (w/w), preferably 30% (w/w), most preferably 40% (w/w), as calculated from density measurement corrected for the alcohol amount;

[0030] b) Subjecting the fraction comprising alcohol and volatile flavour components to a next concentration step comprising freeze concentration, distillation, fractionation, or reverse osmosis, to obtain a concentrated fraction comprising alcohol and volatile flavour components and a leftover fraction;

[0031] c) Combining the retentate from a) with the concentrated fraction comprising alcohol and volatile flavour components from b) to obtain the beer concentrate.

[0032] In a particular embodiment, the method for preparing alcohol-enriched beer concentrate, said method comprising the steps of:

[0033] a) Subjecting beer or cider to a first concentration step comprising nanofiltration to obtain a retentate and a fraction comprising alcohol and volatile flavour components, wherein the retentate is characterised by the concentration of unfilterable compounds equal to or higher than 30% (w/w), preferably 35% (w/w), most preferably 40% (w/w), as calculated from density measurement corrected for alcohol amount;

[0034] b) Subjecting the fraction comprising alcohol and volatile flavour components to a next concentration step comprising freeze concentration, distillation, fractionation, or reverse osmosis, to obtain a concentrated fraction comprising alcohol and volatile flavour components and a leftover fraction;

[0035] c) Combining the retentate from a) with the concentrated fraction comprising alcohol and volatile flavour components from b) to obtain the beer concentrate.

[0036] In some cases it is desired to store the retentate and concentrated fraction comprising alcohol separately until redilution of the beer, in such instance the ratio Xfinal is the one measured after recombining the retentate and the concentrated fraction comprising alcohol together with a diluent.