Mechanism of double pile accumulation affecting fermentation of sauce-flavor Baijiu

In the process of the sixth rounds of high temperature accumulation of sauce-flavor (Jiangxiangxing) Baijiu, the large pile and double pile stacking fermentation of the two groups of piles was carried out, and the effect of increasing specific surface area on sauce-flavor Baijiu during brewing process was investigated. The results showed that compared with large pile stacking, double pile stacking improved the quality of sauce-flavor Baijiu base liquor. According to the analysis results of fermented grains, the double stacking method could enrich microorganisms in the environment because of its larger specific surface area, thus changing the microbial diversity of fermented grains. The relative abundance of Bacillus, Kroppenstedtia and Virgibacillus, which had positive effects on the production of sauce-flavor Baijiu was increased. The analysis of base liquor showed that the contents of esters, alcohols, acids, aldehydes, ketones and tetramethylpyrazines in base liquor could be improved by double pile stacking with larger specific surface area. The tetramethylpyrazines contents reached 1.82 μg/ml, but was not detected in the large pile control group. Finally, the flavor of the base liquor of double pile stacking group was outstanding, and the liquor body was mellow.