Effect of recycled yeast inoculum on fermentation and quality of red wine produced from Punjab purple (Syn H516) grapes

Abstract

Fresh and<b style="mso-bidi-font-weight:normal"> </b>recycled yeast (<i style="mso-bidi-font-style:normal">Saccharomyces cerevisiae</i> MTCC 11815) inoculums were compared for fermentation of Punjab purple (Syn H516) grapes juice for preparation of red wine. An inoculum size of 10% of recycled yeast was optimized for an ethanol production of 9.5% (v/v) at a fermentation efficiency of 74.53% with stored juice and the same was consistent for up to two recycling lots. The prepared wine was allowed to sediment for 7 days at 4^oC, siphoned and filtered and then matured for 6 months in amber colored bottles. A significant decrease in ethanol, total phenols and yeast count was observed in wines prepared from both fresh and recycled yeast inoculum during storage. Both the type of wines scored 65.9±8.01 and 63.3±8.52 on sensory analysis for fresh and recycled inoculum, respectively and were significantly better than a commercial red wine. The red wines were also found to be rich in 10 amino acids.