[BOOK] Flavor Profile #3: Douchi black bean sauce

 Douchi black bean sauce – Cantonese style (豉汁)

Introduction

Douchi (“豆豉”, Dousee in Cantonese) are often translated as 'black beans', but - to the confusion of many befuddled shoppers in the Anglosphere - have precisely zero to do with those sorts of black turtle beans that'd go in something like a Brazilian feijoada. Douchi are fermented soybeans, and could perhaps be thought of as a cousin of soy sauce.

Much like soy sauce, douchi are made by cooking soybeans and leaving them out to let nature to work its magic.

Below are the overly general steps of how douchi is made. This is far from a comprehensive discussion on douchi making but rather a quick summary with broadest strokes.

First, it’s made with yellow soy bean or black soy beans. The beans would be soaked for a couple hours, then steamed or boiled until you could easily break it apart with your fingers.

Next, it’ll be strained and cooled down to roughly 35 degrees centigrade. Traditionally, people would then often wrap that up with tofu cloth, cover it with hay, and put it in a warm place (usually over the counter of that traditional wood fire stove) for at least seven days for the fungus or bacteria to grow naturally. But nowadays, commercial “starters” are also widely used, which consist of either a fungal or bacterial base.

After that seven days then, the beans would then have some obvious fungal strains growing on it. At this point, there’s two main different treatments:

1. Washing off the strain. For this method, people would wash off the strains, dry the beans, add salt and other seasoning, then either (1) sun dry it or (2) directly move onto the next fermentation stage.

2. Keeping the strain. Same deal, either sun dried or moving onto the next fermentation stage. In this treatment, sun-dried douchi patties are a common end product.

For extra flavor, at this point a common additional seasoning is a combination of Baijiu liquor, ginger, garlic, and chili – this makes spicy douchi, which are often seen in Southwest China (Guizhou, Sichuan, Yunnan, and some parts of Hunan).

The time required for the second fermentation stage is usually 30 days, but it can also go on for much longer.

The beans are ready to be consumed after the first seven days fermentation. So, in addition to a longer fermentation, in some areas people would also use the lightly fermented beans directly, with or without the fungus strain on. They’d make a salad with it by adding seasoning and aromatics, or use it in making other dishes. At this stage, the beans are still very much intact that it’d still look like soy beans when served.

Depends on the hydration of the the end product, douchi generally can be categorized into:

1. Dry douchi (干豆豉/gan douchi), no extra water added, fermented directly with seasonings (i.e. the Cantonese type and the ones you'll usually see outside of China).

2. Wet douchi (水豆豉/shui douchi, defined around ~45% water content). To make wet douchi, the douchi cooking liquid is stored separately during the first seven days of fermentation. When mixing in the seasonings right before the second stage fermentation, the douchi cooking liquid is added back to the beans. Shui douchi comes in jars and the brand Lao Gan Ma has it.

Being fermented soy beans, douchi are the same category of things as tempeh and Japanese natto. Tempeh and certain kinds of douchi are fungi based (mucor, aspergillus oryzae, rhizopus, neurospora); while some other kinds of douchi and natto are bacteria based (bacillus subtilis, lactic acid bacteria).

The douchi that you can generally find outside of China are the Cantonese-style sort. The Cantonese one is made with black beans instead of yellow soy bean. It belongs to the dry category. The strains are washed off after the first stage and seasoned mostly with salt. Then in the second stage it’s ferment for about 30 days, after which, it’s dried under the sun, resulting in the small black umami pocket that came to know by most people outside of China.

And above is a general idea of how douchi is made. It's overly simple but douchi making is so complicated that it requires its own book. 

Next, let's quickly touch on the Cantonese douchi black bean sauce. Many people in the West seem to be primarily exposed to douchi in pre-made sauce form - Lee Kum Kee's 'Black Bean Garlic Sauce' seems to be an especially common choice. And while I certainly wouldn't judge anyone for reaching for a shortcut, pounding together some Douchi with garlic is incredibly easy to do at home. And it really is one of those ingredients sort of like whipped cream where doing so can make a palpable difference to the end result.

The most basic version of this 'sauce' is literally just made by simply mincing up some Douchi and garlic, and using that as a base for stir-fries and the like. And even if you do just that and no more, I promise that the flavor will be miles better than the bottled sort. But in order to make things more convenient to work with, we personally like using a mortar to pound the Douchi and garlic together with soy sauce, sugar and salt – the resulting paste can be used as a direct substituted for the jarred stuff.

This base flavor goes excellent with Chenpi (dried and aged tangerine peel, ginger, shallot, and fresh mild chilis. You can use it as a base for a stir fry, or you can smother it over things and steam them. In addition to Chenpi, other citrusy flavors can also be added to the douchi and garlic combo like lemongrass or the yellow parts of lemon skin.