Guizhou Kaili Sour Soup (Kaili Suan Tang) Tradition
Kaili, Guizhou Province — Miao-Dong minority tradition
The Miao-Dong sour soup tradition of Guizhou produces suan tang through long fermentation of rice water, tomatoes, or fish — a living culture of bacteria producing lactic acid over weeks. Kaili suan tang is the most famous regional variant: tomato and chili ferment for the base, cooked with fish (typically grass carp), vegetables and wild greens.