​Polyphenols in beer mainly come from barley and hops. About 80% of them come from barley and 20% from hops. The phenols in barley are about 0.1% ～ 0.3% of its dry weight, mainly distributed in wheat husk, aleurone layer and endosperm. With the dissolution of malt in the process of malting, it is free and brought into wort and beer through the saccharification process. Phenolic substances in hops account for 4%~10% of the dry matter, mainly distributed in the bracts and rachis of hops.

Flavor from yeast and beer fermentationYeast cells are not the final product in beer production, but are indeed important to the quality of the final product beer. The most important thing in the selection of yeast production strains is the speed of fermenting wort and the degree of fermentation of wort.

Control of sterile airBacteria are generally attached to the dust in the air and spread through the air flow, so it is necessary to purify the air; it is advisable to collect air at high altitude, use filter cotton to perform rough filtration, compression, cooling, multi-stage oil-water separation,

Measures to Improve Beer Flavor StabilityDuring the storage process of beer, its flavor will change to a certain extent. In order to ensure its flavor, it is necessary to improve the flavor stability of beer.Control of Oxygen Intake During Wort Preparation