Northern China (Sichuan and Huaiyang traditions both claim it). The soup appears in various regional Chinese cookbooks from the Song Dynasty (960-1279). In Sichuan, the heat comes from chilli as well as pepper; in northern Chinese versions (the internationally known standard), white pepper is the only heat source.
Hot and sour soup (suan la tang) is the perfect balance of sour, hot, salty, and savoury — vinegar-acidulated pork broth with silken tofu, wood ear mushrooms, bamboo shoots, lily buds, and egg. The heat comes from white pepper, not chilli, and the sourness from Chinkiang (black) vinegar. The soup should be tightly thickened with cornstarch — it should coat a spoon without being gluey.
Hot and sour soup is typically a starter in a Chinese meal — the beverage follows the main course pairing. As a standalone: jasmine tea, or warm Shaoxing wine.
{"The broth: pork or chicken stock as the base — not water. The protein richness of the broth provides the structure for the vinegar and pepper to work against","Wood ear mushrooms (mu er) and lily buds (jin zhen): soaked in warm water, then shredded. These two dried ingredients are the textural signature of the soup","Bamboo shoots: canned or fresh, julienned — adds crunch","Egg drizzle: beaten egg drizzled into the simmering soup in a thin stream while stirring in circles — this creates the characteristic wispy egg ribbons throughout the soup","Cornstarch slurry: added to the soup at the end to thicken — the consistency should coat the back of a spoon with a 2mm layer","Final balance: Chinkiang black vinegar (added off heat to preserve the volatile acidity), ground white pepper — the heat comes from the white pepper, not chilli"}
The moment where hot and sour soup lives or dies is the final seasoning — add the Chinkiang vinegar off heat, taste immediately, and adjust. The soup should be unmistakably sour with a lingering white pepper heat. If the sour fades within 10 seconds of tasting, add more Chinkiang. The vinegar should stay present from the first sip to the last.
{"Using rice vinegar instead of Chinkiang: rice vinegar is sharp and one-dimensional; Chinkiang is complex, slightly sweet, and has a distinctive depth from the fermented wheat","Adding vinegar during cooking: the volatile acids evaporate. Add off heat","Over-thickening: gluey hot and sour soup is one of the most common restaurant failures"}