Of the volatile acids known in beer, acetic acid appears to be the most abundant. The acetate content of lager beers has been reported in the range of 20 to 150 mg/1. The effect of the following variables on the formation of acetate during fermentation was studied: yeast strain, wort aeration, pitching rate, and fermentation temperature. The results were evaluated using biometric analysis. On the basis of the analysis of variance, the influence of wort aeration is less than that of the yeast strain, whereas pitching rate and fermentation temperature have more importance than the yeast strain. Based on multiple regression analysis, 80% of all the acetate produced can be attributed to the following factors: glucose + fructose + sucrose, absorbed isoleucine, absorbed tryptophan, excreted sodium, utilized manganese, absorbed arginine, yeast growth, utilized calcium, utilized magnesium, and fermented maltose.