Temporal and Workshop Heterogeneity of Microbial Communities with Physicochemical Properties and Flavor Substances During Stacked Fermentation of Sauce-Flavor Baijiu

Even within the same round of stacked fermentation, variations among production workshops can significantly influence microbial communities and physicochemical parameters. In this study, stacked fermented grains from the fourth round of sauce-flavor Baijiu production were utilized to explore the impact of spatial variations on fermentation. High-throughput sequencing technology was employed to comprehensively analyze the microbial community composition and its dynamic changes during the fourth cycle of stacked fermentation in sauce-flavor Baijiu across different workshops. Our results revealed that the predominant genera in both workshops included <i>Saccharomycetales</i>, <i>Thermomyces</i>, <i>Monascus</i>, <i>Ascomycota</i>, <i>Kroppenstedtia</i>, <i>Bacillus</i>, and <i>Virgibacillus</i>. Differences in physicochemical factors during the fermentation process led to distinct microbial successions among workshops. Key drivers of dominant microbial community succession, such as glucose, starch, ethanol, and temperature, were identified during the fourth round of stacked fermentation. Differences in the types and contents of significant flavor substances in different workshops are related to the complex role of the microbial community. Acetic acid is the most different flavor substance in both workshops, and the content of acetic acid affects the synthesis of ethyl ester substances, which has significant correlation with the regulation of fungal communities, especially <i>Saccharomycetales.</i> These findings provide valuable insights into the brewing mechanisms of the stacked fermentation process and offer guidance for formulating more refined control strategies to optimize the liquor-making process.