Sensory properties of 6- and 18-month-stored wines made with pectinase-producing non-Saccharomyces yeasts

Recently, the use and commercial availability of non-Saccharomyces yeasts (NSY) in winemaking to reduce alcohol content have increased. However, research exploring the influence on sensory quality of the wine, particularly during storage, is limited. Therefore, the objective of this study was to characterize the sensory profiles of Merlot and Chardonnay wines made with pectinase-producing NSY, with added substrate, that is, pectin. Apple pectin (0 or 0.5 g/L) was added to Merlot and Chardonnay grape musts after inoculation with (a) only Saccharomyces cerevisiae or (b) a three species mixture of NSY; after 3 days, S. cerevisiae was added. Addition of NSY with added pectin resulted in higher concentrations of d-galacturonic acid and glycerol concentration in the wines after 6 months of aging. However, mouthfeel (viscosity or weight) of wines with or without added pectin as determined by a sensory evaluation panel was not altered by the presence of these yeasts. Significant interactions among the yeast utilized, pectin addition, and 6-month aging affected some flavors (solvent) of Merlot, while addition of NSY increased other attributes (cherry) during aging. No sensory differences were perceived among Chardonnay samples due to NSY; however, aging from 6 to 18 months increased the intensity of 40 sensory attributes. Though mouthfeel was not specifically affected, the utilization of NSY may be a useful tool to alter wine quality in Merlot by increasing specific aromas during storage. PRACTICAL APPLICATION: We found that must fermented with pectinase-producing non-Saccharomyces yeasts (NSY) modified the chemical composition of the final young wine. After one additional year of aging, an increase in cherry flavor was observed in Merlot wines made with NSY, which may increase perceived quality. Thus, the use of these pectinase-producing NSY may be a useful tool for winemakers.