Fermented black soy beans (豆豉 -dòu chǐ) are a local specialty, with the nearby town of Huangyao being said to have the best. How they measure that, I don't know.
A couple of days ago, I visited the town and saw part of the process. Thought I'd share where and how your Chinese black bean sauce starts out. These images were taken by a press photographer friend who was with me. Here the already fermented beans are being laid out out to try in the sun.
I'll just add that the bottled black bean sauce is rare in China. People buy the beans and make their sauces in the wok along with the other ingredients.
