Study About A New Method Of Brewing Alcohol-Free Beer

From the year of 2002 , China has been the biggest beer output country for 5 years in the world, the varieties of products have also shown a trend of diversified development. In recent years, the World Health Organization appealed people to reduce the consumption of alcoholic beverages , people have also been aware of the harmful effects of alcohol. The consumption of beer and other alcoholic beverages has gradually dropped in Europe and the United States, the yield of alcohol-free beer increases gradually.We want to study and produce the alcohol-free beer concentrated liquid, combining the advantage of the limited fermentation method and the vacuum distillation method. We dilut the concentrated liquid into alcohol-free beer and contrasted it with several varieties of alcohol-free beer in the sensory, also analyzed the statistical results with mathematical method, the conclusion is that they are quite similar in quality. We study detailedly the alcohol-free beer in preparation, the content is divided into four portions, the main contents and results are as follows:1. Adopt special mash techniques. In the process of mash, temperature was risen to 72℃directly after protein interregna, glycosylation can be regarded as being over when iodine reaction disappeared, then temperature was risen to 78℃and filted finally. Give up the time scope from 62℃to 68℃in which fermentable sugar is produced as the optimum reaction time, in order to limit the fermentable sugar to be produced.2. Producing green beer by limited fermentation. When the degree of sugar go down 1-2°P, cool down immediately in order to limit the amount of alcohol in beer. At this time, the metabolites of yeasts are similar with beer, diacetyl contents is not high too, which can be reverted to the required standard during storage.3. The concentrated liquid of alcohol-free beer is prepared by vacuum distillation. The best condition is also determined in the vacuum distillation, such as the temperature and the degree of vacuum. Its best concentration is 65°P. Evaporating temperature determines directly the quality of the alcohol-free beer, if too low, the physical and chemical indicators don't got the demand; too high, the beer will be done a lot of damage. We control the best vacuum pressure within 0.05~0.06MPa, and temperature between 64 and 68℃.4. Dilution of the alcohol-free beer's concentrated liquid. After diluting the alcohol-free beer's concentrated liquid with sterile water, we tasted the beer through sensory evaluation, then rank and sorted the results of mathematical statistic, finally we got the best result as follow: alcohol-free beer concentrated liquid should be diluted to 4 °P, then 15% of the ordinary beer is added to modify their tastes, of course, the alcohol content must be controlled below 0.5% (v/v).