Application of fed-batch fermentation in high-gravity brewing

Abstract

Economic demands to intensify the brewing process and increase the fermenter productivity have stimulated interest in high-gravity brewing. However, increasing wort sugar concentration can have a detrimental effect on fermentation performance, adversely affecting yeast physiology and altering the physical and flavor properties of the beer product. Many methods such as: higher pitching rates, higher fermentation temperatures, more efficient aeration than in conventional brewing, and immobilised yeast were used to improve this process. This study focused on the application of fed-batch fermentation in high-gravity brewing. Two fed-batch cultures with different specific gravity of the supplemented worts were examined. The specific gravity after the supplementation was the same. Despite the higher primary fermentation time, both fed-batch cultures achieved higher concentration of ethanol and lower diacetyl content than those in batch fermentation. These resulted in the possibility of increasing the final beer volume and of shortening the maturation time.