Green-Kernel Black Soybeans Steeped in Vinegar

Why people make this tonic

This is one of Bro Niu’s quiet favorites — black soybeans dry-roasted until their skins crack open, then steeped in sweet rice vinegar in a glass jar. In traditional food-therapy thinking, black beans are linked with the kidneys and black rice vinegar is associated with antioxidant support, circulation, and keeping hair dark. It takes about a month and a half before it is ready, but it keeps for a long time and a spoonful a day is an easy habit.

Who it suits / who should be cautious

• Suits people looking for a gentle, traditional kidney-supporting tonic; Bro Niu notes that when the kidneys feel supported, sleep often comes more easily.
• People with stomach ulcers or excess stomach acid should avoid it, since it is vinegar-based.

Why these ingredients (the food-therapy logic)

• Black soybeans (hei dou): Traditionally associated with the kidneys and with keeping hair dark; dry-roasting until the skins split makes them fully cooked and ready to absorb the vinegar.
• Sweet rice vinegar (tian cu): Bro Niu prefers it over plain rice vinegar because pure rice vinegar can feel sharp on the throat; the sweet version tastes much better and helps the beans soften.
• Rock sugar (bing tang): Optional, added to take the edge off the sourness.

Ingredients (1 jar)

Ingredient	Amount	Notes
Green-kernel black soybeans	fill jar ~1/3 to 2/3	dry-roast until skins split
Sweet rice vinegar (or pure rice vinegar)	fill the jar	sweet vinegar is gentler on the throat
Rock sugar	to taste	optional, softens the sourness

Method

1. Rinse the black soybeans, drain well in a colander.
2. Dry-roast them in a clean dry wok over low heat for about 10 minutes, until you smell the aroma and the skins crack open. (A little browning is fine; do not let them scorch.)
3. Let them cool, then put them in a clean glass jar, filling it about one-third to two-thirds full.
4. Pour in vinegar to fill the jar; add some crushed rock sugar if you like it less sharp.
5. Keep in a cool place (no need to refrigerate if dry-roasted and steeped in sweet/sugared vinegar). Steep about a month and a half before eating.

Bro Niu’s tips

Every day or two, give the jar a gentle shake — otherwise a layer of protein can float to the surface. That floating protein is edible, but regular shaking keeps it from forming. The beans near the bottom sit in the vinegar and turn softer; the ones on top stay firmer but encourage more saliva when chewed, which is fine. Steeped properly it keeps for about a year (Bro Niu says even longer in the fridge, as long as there is no mold or off smell).

Community questions answered (selected)

• Q (Micky): Which vinegar should I actually use to steep black soybeans? Bro Niu: You can use pure rice vinegar, but I find it a bit sharp on the throat, so I steep mine in sweet vinegar — it tastes much better.
• Q (Shirley): Do I have to keep the black soybean vinegar in the fridge? Bro Niu: If you dry-roast the beans until the skins split and steep them in sweet vinegar (or vinegar with plenty of rock sugar), it will not spoil easily and does not need refrigeration. Otherwise it can go moldy, so refrigerate it.
• Q (yee): Is there any difference between aged vinegar and black rice vinegar, and who should avoid black rice vinegar? Bro Niu: Both are beneficial — traditionally associated with antioxidant support, metabolism and balancing the body. Black rice vinegar is also linked with keeping hair from thinning. People with stomach ulcers or excess stomach acid should avoid it.

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Published January 4, 2012 · Adapted and translated for Nourilo from a traditional home-kitchen recipe. Approx. 3 min read.