Selection Of Dry Red Wine Saccharomyces Cerevisiae And Its Brewing Characteristics

In this study,106 strains with typical yeast characteristics were isolated from grape fruits,root soil and natural fermented mash from 8 different regions,including maile city of yunnan province,panzhihua city of sichuan province,yantai city of shandong province and bayannur city of Inner Mongolia autonomous region.After a series of screening for yeast fermentation strength,tolerance and basic pHysiological characteristics,and combined with preliminary identification,it was applied to the small-scale brewing experiment of cabernet sauvignon wine,and commercial yeast was used as the control.In this paper,the pHysical and chemical indexes of wine fermented by saccharomyces cerevisiae were studied.1.After a series of screening of 106 strains of yeast isolated for fermentation strength,tolerance and basic characteristics,5 strains with excellent comprehensive characteristics were finally screened out,namely AT5,AM5,AN6,MJ2 and CT4.Among them,CT4 could be fermented within 24 hours,and the remaining 4 could be fermented within 12 hours.All the 5 yeast strains were resistant to 16%vol alcohol and 60%glucose.Among them,AM5 can withstand 350mg/L sulfur dioxide,and the remaining 4 strains can withstand 400mg/L sulfur dioxide.CT4 could tolerate the acidity of pH2.2,and the remaining 4 could tolerate the acidity of pH 1.7.AT5 and MJ2 can withstand 42? high temperature,CT4,AN6,AM5 can withstand 39? high temperature;The five yeast strains were all high-yielding alcohol yeasts,among which AT5 and AN6 showed low hydrogen sulfide yield and high flocculation,while AM5,CT4 and MJ2 showed middle hydrogen sulfide and medium flocculation.AM5,AT5 and CT4 are low-yielding bubbles,while AN6 and MJ2 are middle-class bubbles.The results showed that MJ2 was bayer zygote yeast,CT4 was spore-hanson yeast in grape juice,AM5 and AN6 were dierspore-round yeasts,and AT5 was lutean yeasts.2.Five selected strains of saccharomyces cerevisiae and commercial yeast were tested for small cabernet sauvignon wine fermentation at room temperature,and the pHysicochemical indexes in the process of wine fermentation by different strains were monitored.After 15 days of fermentation,the residual sugar content of fermented wine of all strains,including commercial bacteria,decreased to?4g/L,the alcohol content ranged from 14%vol to 14.5%vol,and the total acid content ranged from 6.39 to 7.0 g/L.Among them,the lowest residual sugar content of AT5 fermented wine was 3.23g/L,the highest alcohol content was 14.5%vol,the acidity of 6.91 g/L was higher than that of DS,slightly lower than ES488,but the overall difference was not significant.3.Among the 5 strains of selected saccharomyces cerevisiae and 2 strains of commercial yeast respectively fermented cabernet sauvignon wines,55 kinds of aroma components were detected,among which the relative content of alcohol was the highest in iso-amyl alcohol,and the relative content of ethyl acetate was the highest in ester.The contents of acids,aldehydes,pHenols and substances in the fermentation broth of all test strains were not significantly different from those of the commercial fermented liquor.The largest proportion of alcohols was AN6.The relative contents of esters in AT5,CT4 and MJ2 fermented wine were 54.68%,46.543%and 40.261%,respectively,which were higher than those of the two commercial yeast strains.Combined with the results of sensory evaluation,the cabernet sauvignon made by strain AT5 was clear,purple,typical,rich in aroma,smooth and long in the mouth,with a score of 89 points,higher than 2 commercial yeasts.It is suitable for wine brewing and can be used as commercial saccharomyces cerevisiae.