A note on a selective medium for wine yeasts

Abstract

The numerical assessment of wine yeast in the presence of excessive numbers of apiculate yeasts has been attempted by the use of a differential medium. Medium ESY containing 150 mg/l bisulphite and 12% by volume of ethanol (pH 5·5) was found suitable for the enumeration of wine yeasts when present even at low concentrations in the natural microflora during the early stages of a grape juice fermentation. Apiculate yeasts seem to persist longer at low fermentation temperatures.