A Simple Preparation Method of Active Dry Yeast for Wine Making

Active dry yeast is the key auxiliary material for wine production, a system of simple preparation of Saccharomyces active dry yeastbased on “shaker-oven” was constructed using Saccharomyces cerevisiae wh-2-8, selected from Wuhai region, as test material: In the shaking stage, the growth of S. cerevisiae was maintained by adding carbon source and controlling the pH of fermentation process. In the drying stage, the most common blast drying oven was selected as the drying equipment. The conditions were: Yeast Extract Peptone Dextros was fermentation medium, shaker speed 250 r/min, culture temperature 30 ± 1 ℃, intermittent replenishment to maintain glucose at 20 g/L, pH 5～6, fermentation time 55 h. The drying conditions were: 8% of the amount of protective agent algae sugar added, the drying temperature of the blast 36 ℃, drying time 12 hours. Using the optimized technology platform, the maximum dry weight of yeast was 17.80 g/L, active dry yeast with 71% livingcell rate. The results showed that the alcohol content was more than 12%(V/V), the residual sugar of dry red wine was less than 4 g/L, and the volatile acid was far lower than the national standard(1.2 g/L).