Sichuan preserved vegetables — paocai (pickled vegetables in a paocai jar), zhacai (Sichuan preserved mustard tuber), and ya cai (Yibin preserved mustard greens) — form the backbone of Sichuan seasoning. Each is produced through a different fermentation or preservation method and used in different applications.
**Paocai (Sichuan pickle jar):** - Brine jar (paocai tan) maintained with a water seal that prevents oxygen entry — the same anaerobic fermentation principle as German sauerkraut. - Vegetables (cabbage, carrot, radish, celery, green beans) added and removed continuously — the jar's resident microbial community (Lactobacillus) ferments each new addition in 1–3 days. - The brine is maintained with salt additions and refreshed with fresh water as needed. **Zhacai (preserved mustard tuber):** - Mustard stem (not the leaf) — massaged with salt and dried chilli, then sealed and fermented. The specific compressed-and-dried technique produces a firm, crunchy texture even after months of fermentation. - Rinsed before use (very salty). Used in cold dishes, noodle soups, and as a condiment alongside congee. **Ya cai (Yibin preserved mustard greens):** - From Yibin city in southern Sichuan — finely chopped preserved mustard greens with a slightly sweet-salty-fermented character. The defining ingredient in dan dan mian (FD-85) and dry-fried green beans (FD-93).
Dunlop