Studies On Low-Alcohol Beer Brewing

Low-alcohol beer was a kind of functional beverage with 0.5-2.0%(m/m) alcohol content, its flavor and apparent was similar to traditional beer. It was focused on brewing water, raw material and adjunct, additive, mashing process and fermentation process in detail in this pater.Ion content of brewing water was determined continuously in Shiliang Brewery Company in recent years. It was found that the brewing water was suitable for low-alcohol and light beer brewing.It was compared between domestic malt and imported malt for the quality, it was cofirmed that the raw material for low-alcohol beer brewing were Canadian barley malt-Metecafel and Austrilian barley malt-Schooner with relative high (-amylase activity and suitable protein content. The adjunct was rice and oligo-sacchride powder. The proporation of rice adjunct and oligo-sacchride were 25% and 0.67% (mashing wort), respectively.It was researched on mshing process of low-alcohol beer in detail. It was drawn that the iodine value of low-alcohol wort was controlled less than 0.45. The optimal process flow and condition was as follows: the thermo-(-amylase was added to gelatinization tank with the amount of 8u/g rice, mashing-in temperature was 60℃, it was increased to 95℃ for 10min rest, and then to 100℃ for 30min rest. The mashing process was protein rest at 45-46℃ for 60min, adding transglucosidase L-500 with 0.05TGU/g barley malt, and then pumping to the gelatinization tank, the mashing temperature was controlled at 72℃ for 60min rest, then the temperature was increased to 75-76℃ for 10min rest, finally it was pumped to lauter. A brewing yeast strain was screened for low fermentation degree and it characteristics. The beer brewed by this strain was pure and mild. It was found that the taste was the best with 50% fermentation degree. The fermentation temperature was 8.5-9℃, the dissolved oxygen content in wort was 8mg/L, the yeast pitching was 11-12(106/ml. The alcohol content of final low-alcohol beer was about 1.7-1.85%(m/m) in large scale production. The product was welcome in the market.