The total acid in beer comes from the production materials, together with varieties of organic acid produced by applied ajusting acid and yeast metabolism and the reasons for beer rancidity consisted of polluting germs contamination, excessive usage of applied acid and large amount of acid produced by yeast autolysis.

On-line monitoring of different wort concentration and yeast generation by conductivity;

Study on screening of high acetic acid producing strain and its metabolic control fermentation;