Research progress on the construction and maintenance methods of Baijiu mud pits

Mud pits, which are the most widely used in strong-flavor (Nongxiangxing) Baijiu, serve as the carriers of microorganisms during the brewing process. The construction quality and pits degradation during the usage process have a significant impact on the brewing and fermentation techniques as well as the quality of the original liquor. The principles and methods of constructing mud pits, including the selection of site, soil type and configuration, pit-building methods and precautions were systematically clarified. At the same time, the reasons for the quality degradation during the construction and use of pits were analyzed, and the maintenance and daily methods of degraded pits were summarized, aiming to provide references for the construction and maintenance of mud pits, and the improvement of base liquor production quality.