Diversity of Indigenous Saccharomyces cerevisiae Yeast Strains in Cabernet Sauvignon Fermentations from Utiel-Requena Region (Spain) as a Resource to Improve Wine Distinctiveness

The aim of this study was to isolate and characterize autochthonous Saccharomyces cerevisiae yeasts from Cabernet Sauvignon grape must and to analyze how they impacted the final characteristics of the wines obtained from the same type of must. This work was carried out in a "Pago" winery located in Requena, Spain. Twenty-two isolates were obtained from grape must. After molecular identification and typing, 11 different strains were determined. Growth-related parameters and metabolic characteristics (glucose and fructose consumption and ethanol, glycerol and acetic acid production) were determined via laboratory-scale fermentations (50 mL) of Cabernet Sauvignon must. From 2 L fermentation batches, the residual sugar, density, ethanol concentration, titratable and volatile acidities, pH and polyphenolic and volatile compounds were determined, as well as the sensory attributes of the produced wines. Differences between strains in the growth and metabolic parameters were observed. Eleven S. cerevisiae strain profiles were characterized to establish which strain or strains of the selected yeasts would produce the highest polyphenolic and aromatic concentrations of the red Cabernet wines made in the "Pago winery", to then multiply them for their use to make the red wines of this winery.