Study And Application On Beer Active Dry Yeast

In this paper, the screening of beer ADY (Active Dry Yeast) strain, the production techniques of ADY and the applied condition of beer ADY were studied.The fermentation characteristics of nine strains (Saccharomyces cerevisiae SY-1～SY-9) were employed for tests, including flocculation ability, fermentation degree, lethal temperature and fermentation velocity. Strain BY-1 was selected as the best strain. Its bens value was 3.2mL, fermentation degree was 63.2%, lethal temperature was 52℃. The chief fermentation was finished within 4 or 5 days at 12 ℃. The most fast fermentation velocity was 2.5—3.0° P/d.The production capability of SY-1 was determined. The resulted showed that the greatest specific growth rate of SY-1 was 0.285 h^-1 in 12° BX malt extract, and its optimum culture temperature was 28℃, trehaloase accumulation could reach 5.5% in shake flask. The production technique of ADY was confirmed.The applied technology of beer ADY was studied. 12° Bx wort was used as activation solution, ADY was soaked at 35℃ and activated at 30℃ for 2 hours, which were optimum activation conditions. The result that ADY was cultivated at low temperature for one generation was as seam as self-culture yeast. The application quantity of ADY was 0.25-0.50‰.