Potential of yeasts isolated in botrytized grape juice to be new wine yeasts

Abstract

Strains of wine yeast are differentiated based on their ability to ferment grape juice. To advance enology and food technology, many efforts have been invested in the detection and breeding of yeast with high fermentation ability. In this study, we investigated the enological character of 96 yeast strains isolated from spontaneously fermented botrytized grape juice with a high sugar level(35%). The 96 isolates produced wines with ethanol concentrations of 6.7-14.9% (average, 10.9%) from grape juice containing 35% sugar. Among these isolates, KN-35 strains produced 15.8% and KN-94 strains produced 16.2% ethanol in botrytized Kerner grape juice after 50 days of fermentation. Furthermore, we observed that several aroma compounds and higher alcohols present in KN-35- and KN-94-fermented wines were similar to those found in popular wines. The results of this study demonstrated that the KN-35 and KN-94 yeast strains were useful as a starter culture in wine-making, particularly for the fermentation of botrytized grape juice.