Umami-boosters have always played a key role in my cooking. These glutamic acid–rich ingredients—from dried mushrooms to tomato paste to seaweed—are supremely handy, adding complexity to food for little to no extra effort.
Behind the Recipes
Chinese Fermented Black Beans Build Complex Flavor Fast
The power of dau si works to infuse a simple weeknight stir-fry with deep, salty savor.
By Published Feb. 5, 2024.
It’s even better when they’re shelf-stable, because you can keep a wide selection on hand to enhance any meal.
Among my collection of umami-enhancers, Chinese fermented black beans are a favorite.
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Known as dau si in Cantonese (or dou chi in Mandarin), this ancient ingredient is saline, savory, and shelf-stable thanks to a lengthy cure in salt.
The beans boast an aged intensity that is often compared to mature cheeses such as Parmigiano-Reggiano, but the flavor of these wrinkly onyx gems is singular—toss even just a few into a quick stir-fry, and the dish assumes a rich depth that belies its simplicity.
Dau si are beloved in countries across Asia, but some of their most iconic applications come from China’s Guangdong province. There, they give their unique pungency to proteins from steamed spare ribs to braised chicken feet to gingery, peppery clams.
For my own dau si–based recipe, I wanted to center another popular protein pairing—weeknight-friendly shrimp.
Science: How Soybeans Become Dau Si
The nuanced funk of dau si has captivated humankind for over 2,000 years, a flavor that is owed to fermentation. Dau si are made by washing, soaking, and steaming soybeans (often black soybeans) and then inoculating them with koji (Aspergillus oryzae), the ancient mold responsible for miso, sake, and other iconic Asian ingredients. After several days’ incubation while the koji grows, the dau si are salted and fermented for at least half a year, either in a sealed container or in the sun, before they are packaged and sold. During this time, koji enzymes snip the proteins, freeing savory glutamic acid, which imparts umami taste. The mold also produces enzymes that convert starch into sugar, fueling other fermentation organisms (bacteria, yeast) to create additional flavor.
After starting my rice cooker (a base of neutral white rice is a must for this highly seasoned dish), I peeled and deveined a pound of extra-large shrimp. As they marinated in a classic combination of soy sauce and Shaoxing wine, I prepped the rest of the ingredients: ginger, garlic, scallions, and a red bell pepper (for color and refreshing grassy, vegetal notes).
Next, the beans: I rinsed 5 tablespoons of dau si to rid them of some salt and then coarsely chopped them. Finally, I assembled a sauce of chicken broth, oyster sauce, sesame oil, and cornstarch (which would form a gel when heated, giving the sauce glossy body), seasoning the mix with a tablespoon of sugar to amplify the shrimp’s natural sweetness and balance the savory beans.
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Stir-frying was a breeze: I sautéed the aromatics and beans in neutral oil in my wok and then added the peppers, marinated shrimp, and sauce one by one.
Off the heat, I folded in the scallion greens, and then I served myself a bowl of the plump, snappy shrimp and lightly sweet peppers enrobed in silky, ultrasavory black bean sauce. Thanks to dau si, I had a dynamic dish in record time.
