Evaluation of the effects of yeast strain and fermentation conditions on the volatile concentration profiles of pilot plant lager beers

Abstract

The effect of yeast strain, stirring, pitching rate, fermentation temperature, aeration, initial wort pH and lagering on the concentration profiles of the volatile compounds in the resulting beers were studied. Univariate and multivariate analyses of variance were applied to instrumental data to evaluate the differences among samples. Under the conditions used in these experiences, fermentation temperature, stirring of the wort and lagering gave rise to more changes in the concentrations of volatile constituents than pitching rate, yeast or wort reoxygenation. Main interactions were found to occur between fermentation temperature and initial pH, between stirring and pitching rate and between stirring and fermentation temperature. The effect of the different fermentation variables on specific volatile compounds is also discussed.