At the heart of this product is Douchi (豆豉) — naturally fermented black beans. The beans are washed, steamed, then inoculated with natural cultures and left to ferment slowly in a warm environment. They are then packed with salt and aged a second time in jars, during which the surface of the beans turns a deep black and rich umami flavour becomes concentrated within. The resulting Douchi is then simmered together with soybean oil, chilli, and spices to create this chili sauce.
Fermentation is not merely a method of preservation — it is the science of building flavour. As the proteins within the beans slowly break down, naturally occurring umami compounds including glutamate are produced, giving rise to a deep, multi-layered taste that cannot be achieved with plain beans alone. Across southern China, this method of fermenting beans has been practised for hundreds of years, producing an essential condiment for the everyday table.
For a European point of reference, the character of this sauce shares something with long-aged blue cheese, naturally fermented wine, or sauerkraut — all products where microorganisms work over time to craft complexity of flavour. The principle is the same. The aroma may feel unfamiliar at first, but once acquainted, you will find it delivers a depth that no simple salt or chilli sauce can replicate.
