Ethanol

This page is in progress
Please check back later for additional changes

A major factor limiting ethanol production during HG fermentation is ethanol itself. Under HG conditions ethanol levels may be as high as 16% (v/v). The effect such ethanol concentrations have on a cell's fermentative ability is dependent on that cell’s ethanol tolerance, which is in turn affected by a number of factors including the genetic makeup of the yeast strain, the physiological state of the cells and the physico-chemical nature of the fermentation environment. While the traditional view was that ethanol tolerance in yeast strains was determined by genetic differences between strains, with, for example, sake and distilling strains being more tolerant than brewing strains, studies have identified yeast physiology and the cell's environment as being critical to ethanol tolerance; with brewing strains in some cases tolerating concentrations similar to those experienced by sake strains.