FIELD: brewery, biochemistry. SUBSTANCE: invention relates to methods of green beer maturation obtained after fermentation stage and containing α --acetolactate as by-side harmful substance. Method involves decarboxylation of α --acetolactate in green beer. Green beer is contacted with silicon oxide, aluminium oxide, alumosilicate composition or alumosilicate composition containing binding agent at 7-15 C and at ratio of active material : beer mass = (1:5)-200. This provides increase of the rate of decarboxylation of α --acetolactate to acetoin in ready product, i. e. beer maturation. Before contact with active material beer mass is separated from bacterial mass. EFFECT: improved method of decarboxylation, increased rate of reaction. 5 cl, 7 ex
