Acetolactate decarboxylase

Function

Acetolactate decarboxylase reduces the undesirable butter aroma (of diacetyl) in beer. This occurs as a by-product of beer brewing.

Application

Exclusively in the brewing of beer: during the brewing process, the yeast forms a specific substance (alpha-acetolactate), which then forms diacetyl (butter aroma), which is undesirable in beer. During storage, this aroma slowly is converted into a neutral taste note. In order to shorten the conversion time, diacetyl is eliminated by addition of the enzyme.

• In Germany, the use of enzymes during brewing violates the purity laws and therefore is not allowed.

Gene technology

To date, two biotechnologically won acetolactate-decarboxylase specimens are marketed in Europe. They are produced with help of GM microorganisms (bacillus stems, also called brewer’s yeast sccharomyces cerevisae).

Labelling: labelling of enzymes in regard to their production using GM microorganisms is generally not foreseen in the European Union.