Research On Selecting Of Saccharomyces Cerevisiae With High Alcohol And Osmotic Pressure Tolerance And Its Performance

Super high gravity brewing of beer is developing from more and more matured high gravity brewing technology. This technology is usually adopted in foreign country, but seldom used in our country. This paper started with selection of beer yeast, comparison of performance, measurement of the flavor substance after high gravity brewing, study further on super high gravity brewing and super high gravity brewing yeast.This paper takes the yeast mud from a brewery as the starting strain, for long period of time of selection, finally getting a strain of high alcohol resistance and high permeation pressure resistance. Simulate the real fermentation condition with this yeast strain, utilize different concentration wort to culture, observe its growth habit, growth condition and the focculating test under microscope, measure its growth curve, mortality rate, temperature quenching, extreme fermentation degree and alcoholic strength under higher concentration and lower concentration, the assimilation ratio of a-amino nitrogen, the flavor substance after the extremely high concentration fermentation as well as the fermentation for three generations, and taste the flavor. The results showed that:final mortality11°P wort0.893%,20°P wort under0.948%. This high tolerance of brewer’s yeast off the die temperature of48℃. Cohesion11°P wort0.65mL,0.62mL cohesion20°Pwort.11°Pwort final CO2weight loss to3.56%.11°P Pwort limit the degree of fermentation was79.1%, limit the degree of fermentation20°P wort of71%.11°P wort limit fermentation of alcohol and3.4%11°P wort limit fermentation alcohol8.0%. Final a-amino nitrogen assimilation11°P wort was52.19%,20°P wort eventually a-amino nitrogen assimilation rate of44.89%; total brewing time of57world,the inoculated yeast1%,the acetaldehyde content of4.26(mg/L),the total content of higher alcohols73.2(mg/L),total volatile ester of24.18(mg/L), ultra suitable for drinking.