Study on producing vinegar by liquid-state fermentation of raw material.

The new technology of liquid-state fermentation of raw material was used to produce vinegar.The influence on the receipt rate and invert rate of alcohol and acetic acid caused by periods of alcoholic and acetic fermentation,proportion of raw material,usage of lees and temperature were considered.The method mentioned above was employed to determined the optimal technological conditions of the vinegar.The optimal conditions for two-step liquid-state alcoholic and acetic fermentation were found as follow:periods of alcoholic fermentation 12 d,temperature 30～32 ℃;periods of acetic fermentation 15～20 d,temperature 32 ℃.The proportion of raw material:rice 18.18%,bran 3.64%,lees 1.45%,acetic bacterium 4.00%,water 72.73%.The optimal conditions for one-step fermentation were as follows:periods of bilateral fermentation 20～25 d,temperature 30～32 ℃.The proportion of raw material was as follow:rice 18.18%,bran 3.64%,lees 1.45%,acetic bacterium 4.00%,water 72.73%.Comparing With the traditional technology showed that liquid-state raw material fermentation to pruduce vinegar can be more effective in saving energy,reducing labor intensity,simplifing the process.