Studies On The Production Of Acidified Malt With The Use Of Lactobacillus Plantaru

The production of acidified malt was studied in this research. The dry malt was immersed in acidified wort that produced by L. plantarum 6009 for a certain time 35癈, dried, then acidified malt was obtained. The acidity of finished acidified malt was 1.5%-2.5% (lactic acid). The acidified malt was used as a substitute for mash acidification. The main results were as follows:1 Aerobic plate count method was used to determine the growth curve of L. plantarum 6009. The results show that the bacterium entered logarithmic, stationary, and decline phase after being incubated for!2h, 24h, and 36h at 35癈, respectively.The 24-36H incubation was selected as the optimum inoculation period.2 The optimum condition for lactic acid production of L. plantarum 6009 was: 1 l癇rix wort, 5-10% inoculums size, incubation at 35癈.3 The studies on the trend of lactic acid production after initial acidified wort with different content of acidity was compensated with fresh no hopped wort indicate: L. plantarum was most active and produced acid most quickly when the 0.7% acidityacidified wort was compensated with 90-95% fresh no hopped wort.4 Physical and chemical indexs of acidified malt that immersed by 0.7% acidity acidified wort for 48 hour show: all the indexs such as acidity, a-AN, extract of acidified malt matched the goal. Acidified malt immersed by acidified wort containing 0.7% acidity for 24h and 48h contain 1.7% and 2.5% acidity, respectively.5 Addition of different dosage of acidified malt or immersed liquid into mash to imitate mashing experiment. The results indicated: alO% acidified malt or 1.2-2.0% immersed liquid can adjusted pH of mash to 5.65-5.45.6 the comparison of lactic acid production with wort added by 30% rice and wort show that the former produce less acid than the latter. Considering the purpose of this50research and the economic factor, malt culms, (NH4) 2HP04, yeast extract powder were selected as supplement for Nitrogen. An optimizing medium was obtained via revolutionary design generally used. Factor codes worth was: 1, 1.682, and 1.682; the optimized dosage of malt culms, (NEi) 2HP04, yeast extract powder was 39.86(g/L),0.4(g/L), 10(g/L), respectively.7 Beer were brewed by wort whose pH value adjusted by acidified malt and immersed liquid on a small-scale. The finish beers had clear and transparent appearance, spotlessly white and fine foam, pure and fresh taste, soft and good-balance.