Sour Flavors from Earth and Jar
Aged vinegars, earthenware sour soups, wild forest papayas, and fermented bamboo shoots: each region cultivates acidity to wake the appetite and preserve the harvest.
Chinese cuisine is often described as salty or spicy: where does all the sourness come from?
Sourness grew from climate and preservation. Earthenware crocks allowed wild yeasts and lactobacilli to flourish, turning grain into mellow vinegar, mountain papayas into crisp relish, and river fish into zesty sour soups.
The useful thing for a traveller is that sourness travels badly. A bottle of Shanxi vinegar will survive the flight home. A bowl of Kaili sour soup will not, which is roughly the difference between a cuisine you can buy and a cuisine you have to go to.
That is also why the sour dishes are the hardest to describe in English. There is no reference point in the European kitchen for ‘fermented bamboo shoot’, so a description has to be a smell, and a smell does not travel in text either.
Local variations
Red sour soup: tomatoes and chillies fermented together, then boiled with fish. Sour before it is hot.
Damp, no salt, no sun to dry with — fermentation was the only way to keep a winter's worth of vegetables. It became the base of the local cuisine.
Sorghum vinegar aged in ceramic jars for years. Every household keeps a bottle of it like a condiment, not a delicacy.
The dry loess plateau grows sorghum better than it grows rice, and the long ageing is only possible in a climate with a stable cold cellar season.
Pickled bamboo shoots — the smell that made the city's noodle soup famous and keeps half the room away.
Napa cabbage fermented whole in a stone jar, buried before the first freeze and dug out all winter.
Sour papaya simmered with fish — sourness from fruit rather than from fermentation.
Siwawa red sour soup: wild mountain tomatoes fermented naturally inside earthen jars, seasoned with houttuynia root.
Complex natural fruit acids enliven shredded root vegetables, providing sharp refreshment amidst humid karst hills.
Zaopocu hotpot: rice wine lees secondary-fermented into a tangy broth, poaching fresh sea fish and squid.
Tropical temperatures foster lactic fermentation in rice lees, yielding delicate organic acids that tenderize marine catch.
Dark buckwheat noodles press directly into boiling cauldrons, chilled in iced beef broth.
High-fat yak milk simmers in wide vats before setting in ceramic bowls; natural fermentation forms an unctuous golden butterfat crust.