Influence of Native S. cerevisiae Strains on the Final Characteristics of "Pago" Garnacha Wines from East Spain

This work studies the variability of the Saccharomyces cerevisiae present during the spontaneous fermentation of Garnacha grapes' musts from a "Pago" winery from the east of Spain. The parameters used to select yeast are those related to growth, fermentative behaviour, and the influence on the wine's aroma and polyphenolic composition. Yeast identification was performed by ITS analysis and typed by Hinfl mDNA restriction profile analysis. Growth and metabolic characteristics of the isolates were determined by laboratory-scale fermentations of sterile Garnacha must, and the composition of the polyphenolic and the volatile compounds, and the sensory attributes of the small-scale produced red wines were determined. Ten S. cerevisiae strains were isolated and characterized. Overall, strain 22H quickly grew, produced wines with moderate ethanol concentrations and low volatile acidity, and obtained the highest colour and aroma scores, plus a high score for sensory attributes.