THE REDUCTION OF DIMETHYL SULPHOXIDE TO DIMETHYL SULPHIDE DURING FERMENTATION

Abstract

Dimethyl sulphide (DMS) produced by yeast during fermentation is formed from dimethyl sulphoxide (DMSO) rather than from S‐methyl methionine (HADMS). All the yeasts and one of the two spoilage organisms examined formed DMS from DMSO. In fermentations at 8°C only 13–21% of the DMSO is reduced to DMS by yeast and the extent of conversion is greatly decreased by raising the fermentation temperature. The amount of DMS formed increases as the gravity of the wort is raised but is also dependent on the fermentable sugar employed. There is therefore no simple correlation between DMSO content of the wort and DMS formation. 1980 The Institute of Brewing & Distilling