The Preliminary Study On Fermentation Process Of Micro-beer

Micro-brewing beer is popular to people with the characters of small investment,unique tecnology and rich nutrient. In this paper,brewing water,yeast screening and performance comparison, saccharification and fermentation process had been studied.In this study, based on the analysis of groundwater in Nanchang, we have summed up the appropriate operating procedures. The improved water is fit for the requirements of beer brewing.Compared with fermentation performance of beer yeast strain JA, JB, JC,which were mutated by the UV,we have tested killing temperature, cohesion, mortality, capacity of return diacetyl, fermentation speed, the contents of higher alcohols and ester, physical and chemical properties of fermentation on three different yeast strains.Results showed that the best comprehensive performance strain is JB, which has the potential application in beer production..We studied the optimization of micro-beer saccharification. By doing single factor experiments of crushing degree, temperature, pH value,we studied the influence of the three factors to malt saccharification.Then we used full factorial experimental design to select the important factors on the saccharification--crushing degree, saccharification temperature and the ratio of water, and determined the optimal level. The optimized saccharification process was as follows:grinding grain diameter 0.5mm, temperature from 35℃gradually rise to 74℃, pH value of 5.5, the ratio of water to 1:4, the wort concentration to 18.62, non-sugar and sugar ratio to 0.35.Using the wort produced by optimized mashing proces,we carried out the experiments of beer fermentation.The result showed that the beer had a soft pure taste.We studied the optimization of micro-beer fermentation.The impact of inoculation,the initial sugar content, fermentation temperature to sensory evaluation of beer and fermentation speed was researched. Then we optimized the fermentation process of micro beer by orthogonal test.The result showed that when the best micro beer fermentation conditions were:inoculum of 10%, fermentation temperature of 15℃, nitial sugar content of 14°Bx,the beer tasted pure, soft,refreshing and strong flavor.