Screening And Application Of Low-yield Higher Alcohol Vitis Yeast Cerevisiae Strains

In order to get Saccharomyces cerevisiae strains of Vitis davidii Foex of Low Yield Higher Alcohol,90accharomyces cerevisiae strains were extracted from unblended wine of davidii Foex, fresh davidii Foex and grape residue left after being primarily fermented and filtered. The primary selection and the comparison of performance measurement of these90strains were carried out. Through potato juice fermentation test, the fermenting power of the strains was contrasted. And then the alcohol tolerance, sugar tolerance, acid resistance and resistance to sulfur dioxide were compared.According to results,3good fermentation performance strains(A16、B54、D70)were screened out.Put these three strains through the next fermentation tests of different pH value、inoculation amount and temperature on the influence of higher alcohol.Finally,2good fermentation performance strains(A16and D70)were screened out.When the inoculation amount is6%,both of A16and D70strains were low-yield higher alcohol;when the temeprature is20℃,both of A16and D70strains can start fermentation quickly and low-yield higher alcohol;meanwhile,both of A16and D70strains produced appropriate higher alcohol when the pH value is3.0.For these reasons, A16and D70strains were screened out to be used in large scale of producing.The drying techniques of active dry yeast of grape wine A16were studied and the results suggested the following optimum conditions:The inlet temperature of fluidized bed was set at80℃. The protective agent used for ordinary ADY was a combination of3%monoglycerides3%, Tween-80and5%trehalose,water content after drying controlled in5.0%, and living cell rate reached about82.3%.At the same time, relying on the original wine production process and selecting A16as the experimental strain, through singlefactor and the orthogonal test of changing fermentation temprature, yeast inoculation amount,pH and grape juice sugar content, found out the optimal conditions for the fermentation of wine were:fermentation temperature24℃;yeast inoculation amount6%;pH4.0and grape juice suger content24Brix.