I've written before about the Miao people* who live just to the north of here. Here is a brief extract from a guide book to the area. Note that when they say 'sour', they mean 'pickled'. In Chinese, the word is the same -. 酸 (suān).
Here is another excerpt from the Food Funnies topic in which a small typo changes the whole concept.
Harvest Lunch in a Miao Village