SOME EFFECTS OF AERATION ON THE CONTINUOUS FERMENTATION OF HOPPED WORT

Abstract

Oxygen has been supplied to yeast growing in a single‐stage open continuous fermentation system either in solution in the wort or, in larger amounts, by injection into the fermenting wort. Smaller quantities of air stimulated yeast growth and also led to an increased rate of consumption of sugar and production of ethanol by unit weight of yeast, whilst the specific rate of production of both esters and higher alcohols was not greatly affected. In contrast, the presence of larger quantities of air, although stimulating growth still further, decreased both the specific rate of fermentation and the production of esters, whilst large quantities of acetaldehyde and acetoin were formed. 1967 The Institute of Brewing & Distilling