Characteristics of fermented grains of sauce-flavor Baijiu from Xiasha to the 4th rounds accumulation

In order to explore the characteristics of fermented grains of sauce-flavor (Jiangxiangxing) Baijiu at the end point accumulation in different stages, physicochemical and microbial indicators of fermented grains from Xiasha to the 4th rounds were detected in 53 pits of Guizhou Province distillery, and the correlation between the yield and quality of base liquor at the end point of each round was analyzed. The results showed that with the increase of rounds, the temperature, acidity, moisture and fermentation power of fermented grains showed an obvious increasing trend, the starch content decreased significantly (P<0.05); the content of L-lactic acid and glucose showed an overall increase; the ethanol content, Zygosaccharomyces bailii count and the viability of yeast increased rapidly in the early stage and tended to the level after the 2nd round. The saccharification power decreased first and then the level fluctuated; the total number of Saccharomyces cerevisiae and yeast changed little. The results of correlation analysis showed that there were 10 indicators significantly related with the yield and quality of base liquor (P<0.05), which were water, ethanol, Z. bailii, lactic acid, S. cerevisiae, acidity, starch, glucose, temperature and fermentation power, respectively. Among them, water, ethanol content and glucose content had the greatest influence on base liquor, the effect of water and ethanol content on base liquor was mainly positive correlation, and the effect of glucose content on base liquor was mainly negative correlation.