PRODUCTION OF YEAST MASS DURING FERMENTATION OF WORT BY BREWERY YEASTS

The quantity of yeast dry matter present in fermenting wort increases throughout the period of sugar utilization. During the period of exponential production of new cells and yeast mass the yield of yeast dry matter per mol of hexose utilized (Y_hexose) does not vary significantly for the yeasts and worts examined. In the post-exponential phase, however, Y_hexose declines, to an extent which varies with strain and which is particularly marked if exponential growth has previously been restricted by deficiency of non-carbohydrate nutrients. The total yield is primarily determined by the concentration of the nutrient controlling the extent of exponential growth.