Doubanjiang — fermented broad bean and chilli paste, the defining ingredient of Sichuan cooking — provides the simultaneous flavour of salt, umami (from the fermented beans), and heat (from the chilli) in a single ingredient. The Pixian doubanjiang (from Pixian county outside Chengdu) — aged 3+ years — is the benchmark. The ma la (numbing-hot) principle that defines Sichuan cooking combines Sichuan peppercorn (ma — numbing, from the hydroxy-alpha-sanshool compound that activates and then inhibits mechanoreceptors) with dried chilli (la — hot, from capsaicin).
- **Doubanjiang:** Finely chopped before use — the large pieces of dried chilli and fermented bean must be fine enough to distribute evenly through the dish. - **Frying the doubanjiang:** The paste is always fried in oil before other ingredients are added — 3–5 minutes over medium heat until the oil turns red-orange from the extracted capsaicin and the raw fermented note transforms to a deep, cooked complexity. - **Sichuan peppercorn (hua jiao):** Toasted before grinding — the toasting develops the aromatic compounds (linalool, limonene) while the grinding releases the numbing hydroxy-alpha-sanshool. - **The ma la balance:** The numbing (ma) and the heat (la) must be in balance — too much numbing produces an unpleasant dentist-office sensation; too little produces ordinary chilli heat without the characteristic Sichuan dimension.
China: The Cookbook