Selection of Indigenous Saccharomyces cerevisiae Strains for Winemaking in Northwest China

To avoid the risk for sluggish or stuck fermentations and quality deterioration caused by increasing sugar contents of grape grown in northwest China, a selection of indigenous Saccharomyces cerevisiae strains with excellent enological characteristics could be of great value for the local wine industry. For this purpose, 52 indigenous S. cerevisiae strains, isolated from five wine-producing regions of northwest China, were evaluated for several important enological properties, including stress tolerance, killer phenotype, hydrogen sulfide and foam production levels, and flocculation and fermentation rates. Microfermentations with eight preselected yeast strains were performed on Cabernet Sauvignon. All selected strains could complete fermentations, and the enochemical parameters were within the acceptable ranges of the wine industry. Four strains (XJ3, SAX2, SAX5, and SAX6) produced higher amounts of esters than the control commercial strains, and the corresponding wines were highly regarded by wine judges as having the best sensory quality. The fermentation performance of these strains at high initial sugar concentrations was also analyzed. They could be used as starter cultures, and the selected indigenous strains could potentially improve the regional character of the wine. Moreover, these strains may have the potential to produce wines from grapes with high initial sugar content in the Xinjiang and Ningxia regions of northwest China.