Zhaotong Sauce: Fermentation in Two Stages

A study published in the Chinese journal Brewing Science describes Zhaotong sauce as a soybean paste whose identity is tied to the place where it is made. Its experimental process begins with soybeans roasted, dehulled and milled. The powder is mixed with water and formed into cakes, then covered with straw for roughly twenty-eight days of starter fermentation. The cakes are broken up, combined with seasonings and water, and left outdoors to mature. The researchers describe a total process of about 180 days. This is a documented experimental protocol, not proof that every household or workshop follows precisely the same recipe.

The study’s sequence is unusually legible: roast, mill, form, make the starter, add the sauce mixture, then expose it to sun and night air. It records turning the mixture every three days during the outdoor stage. Researchers sampled the fermentation over time and analyzed volatile compounds using laboratory techniques. They identified changes in the chemical profile as fermentation progressed. Such analysis does not replace a cook’s or maker’s knowledge, but it offers one way to observe how a long process changes aroma.

The Ministry of Commerce’s old-brand digital museum traces the Wanhe sauce business to 1910, when its founder moved from the Sichuan area then known as Xuzhou to Zhaotong. The company profile says the enterprise passed through public-private partnership in 1956 and was restructured as Zhaotong Wanhe Food in 2004. It presents Wanhe’s version of the craft: local pepper, Yanshan green peppercorn, salt and water are combined in earthenware jars, with repeated sunning and turning over about six months. These details describe one company’s practice and self-presentation.

For readers, the two records make the sauce’s history tangible. The laboratory follows a batch through time; the Wanhe archive places one producer within a century of business and changing manufacturing. Neither account stands for every household, but together they show how fermentation knowledge moves between food practice, measurement and a branded product.