Douchi
豆豉 · dòuchǐ (pinyin)
Salted black soybeans that have been fermented whole, sold as dry individual beans and used as a seasoning rather than eaten as a dish.
What it means
Douchi (豆豉) is a seasoning of soybeans that have been salted and fermented; Wikipedia notes that some types are fermented with molds and others with bacteria. The Woks of Life describes the common black soybean kind as individual soft, mostly dry beans in a light coating of salt, not a paste or a sauce.
Wikipedia dates the food to at least 165 BCE, when marked containers were placed in Han Tomb No. 1 at Mawangdui, and The Woks of Life says it predates soy sauce. Cantonese cooks call the same bean dau6 si6. It is a seasoning rather than a dish, because the beans are much saltier than a vegetable would be.
These are black soybeans, not the black turtle beans sold in bags for rice and beans. Wikipedia says the two are not the same food, and The Woks of Life says canned or dried black beans cannot be substituted for douchi.
A common mix-up
Fermented black soybeans are not the black turtle beans sold for Latin American cooking, and canned or dried black beans are not a substitute.
Questions people ask
Is douchi the same as black bean sauce?
No. Douchi is the fermented bean itself. Wikipedia describes black bean sauce as a condiment made from douchi with garlic and soy sauce, so the sauce is a separate product with its own salt level.
Can I use canned black beans instead of douchi?
No. Wikipedia says Chinese fermented black beans are not the black turtle bean, and The Woks of Life says canned or dried black beans cannot be swapped in. Buy a packet of douchi from a Chinese grocer instead.
Sources & further reading
Background and preparation references. Our descriptions are editorial summaries, not restaurant reviews.