Pixian doubanjiang (郫县豆瓣酱) — broad bean paste fermented with chillis from Pixian County in Sichuan province — is often called the soul of Sichuan cooking. Unlike generic chilli pastes, Pixian doubanjiang is fermented for a minimum of 6 months and up to 3 years in ceramic urns open to the air, developing a complex umami depth, a deep brick-red colour, and an aromatic intensity that simple chilli pastes cannot replicate. It is the foundational flavour in mapo tofu, kung pao chicken, twice-cooked pork, and dozens of other Sichuan preparations.
What Pixian doubanjiang contains: Fermented broad beans, fermented chillis, salt, wheat flour, and water. The fermentation process converts the proteins and starches in the beans into glutamates (umami), and the chilli compounds into a more complex aromatic mixture. How to fry doubanjiang (chao douban): The critical technique for Sichuan cooking is the long frying of doubanjiang in oil — typically 2-4 minutes over medium-low heat. This achieves: (1) Extracts the fat-soluble red pigment from the chillis into the oil, producing the characteristic red-orange cooking oil. (2) Drives off the sharp acidic top-notes of the fermented paste, leaving the complex umami base. (3) Develops additional Maillard products from the bean solids. Brands: Pixian doubanjiang from Pi County, Sichuan province is the standard. Widely available brands include Juan Cheng (鹃城牌) — considered the best available internationally. The paste should be deep brick-red, chunky with visible bean solids, and have a complex fermented aroma.
Store opened doubanjiang refrigerated in a sealed container — it keeps for 6 months or more. The surface will develop a thin layer of oil from the fermented beans, which is normal and desirable. For a smoother sauce, finely chop the doubanjiang before frying — this accelerates the colour extraction and produces a more homogeneous texture.
Substituting generic chilli bean paste: Korean gochujang or generic Chinese chilli paste lack the fermented broad bean base and the aromatic complexity of Pixian doubanjiang — the difference in the finished dish is stark. Not frying the doubanjiang long enough: Brief frying leaves the sharp, raw fermented notes. The minimum time is 2 minutes over medium-low heat until the oil is a deep, vivid red.
Fuchsia Dunlop, The Food of Sichuan (2019); Fuchsia Dunlop, Land of Plenty (2001)