Winemaking of musts at high osmotic strength by thermotolerant yeasts

Fermentation performance of 15 thermotolerant Saccharomyces cerevisiae in t hree musts from dried grapes at 25, 30, and 40 degrees brix was studied. Wh en the osmotic strength was increased, the volatile acidity and the SO2 pro duction in the wines also increased: in the must with 40 degrees brix, yeas ts produce from 1.63 to 3.65 g acetic acid l(-1) and from 40 to 73.6 mg SO2 l(-1) due to osmotic stress. From 9.75 to 13.40 ethanol v/v production is observed in must at 30 degrees brix, whereas at 40 degrees brix there is a clear detrimental effect.