Indigenous yeasts perform alcoholic fermentation and produce aroma compounds in wine

The spontaneous alcoholic fermentations of Moscato Bianco and Welschriesling must were carried out to retrieve indigenous yeasts. We confirmed that those fermentations, conducted with non-Saccharomyces and indigenous Saccharomyces cerevisiae yeasts, can generate high amounts of aroma compounds in wines. Consequently, two of the S. cerevisiae isolates were randomly chosen and further examined in Welschriesling and Sauvignon Blanc must for their ability and efficiency in performing alcoholic fermentation. Alcoholic fermentation with a commercial yeast strain was carried out for comparison. Indigenous isolates showed acceptable fermentation ability and efficiency. Moreover, Sauvignon Blanc produced with indigenous isolates contained significantly higher amounts of 3-mercaptohexyl acetate, linalool, geraniol and 2-phenylethanol and a significantly lower amount of 3-mercaptohexan-1-ol. Differences in Welschriesling wine were less striking but in this case indigenous isolates produced lower amounts of 3-mercaptohexan-1-ol and α-terpineol. Taken together, our results confirm that a suitable aromatic profile of wine can be produced with indigenous S. cerevisiae strains.