Analysis of sources of brewing water in core baijiu-producing area of the Chishui River

The main producing areas of Chinese baijiu are mostly distributed in artesian basins, and the groundwater recharge for brewing water exhibits distinct geological characteristics. The contents of minerals and rare earth elements in water body are the primary factors contributing to the regional differences in liquor taste. To investigate the key components and source of liquor-brewing water, multiple geochemical approaches were adopted to conduct hydrochemical analysis, water volume calculation, and hydrogen-oxygen isotopic analysis on surface water and groundwater in the Chishui River Basin. The results show that characteristic mineral components such as strontium, sulfur, and calcium in brewing water originate from water-rock reactions between groundwater and surrounding rock during groundwater migration. More than half of water volume in the Chishui River is supplied by exogenous water, which serves as the main recharge source during dry season; spring recharge area is derived from river seepage water in the Qinghai-Xizang Plateau. The midstream strata of Chishui River host carbonate rock formations containing celestite, barite, and gypsum, which provide sources of strontium, sulfur, calcium, and other substances to water body. It is inferred that seepage water from the Qinghai-Xizang Plateau dissolves minerals such as strontium, calcium, and sulfur from carbonate rocks during transport and converges into Chishui River. The river water is rich in unique minerals and rare earth elements required for brewing high-quality liquors such as Moutai, Xijiu, and Langjiu, endowing Chishui River with its distinctive status as the “river of fine liquors”.