Chinese salted black beans are one of the many products made from soy beans - not, as some people believe, from the dried black 'turtle' beans commonly made into thick winter soups and chillies.
The fermented, salted beans are strongly flavoured, and their distinctive taste is essential in many Chinese dishes. The salting and fermenting process is time-consuming - they are boiled, steamed, fermented, matured and then steamed and dried in the sun several times. When ready, the beans are black and shrivelled, and bear an unpleasant resemblance to rat droppings.
Salted black beans are available whole and sold loose or in small plastic bags. The producer sometimes mixes the beans with other seasonings such as garlic or chilli. They are also made into ready-to-use black bean sauces and pastes sold in glass jars.
Some recipes advise soaking the whole beans in warm water for 30 minutes before using them, and then discarding the liquid. I usually rinse the beans to remove the excess salt, then soak them briefly (five to 10 minutes) in warm water mixed with Chinese rice wine. Instead of discarding the tasty soaking liquid, I usually add it to the dish.
Because black beans are so pungent, they are crushed, mashed or chopped after soaking to distribute the flavour better throughout the dish. They are cooked with other strongly flavoured ingredients such as garlic, ginger, chillies and spring onions.
Some of the more popular Chinese dishes are clams or lobster stir-fried with black bean sauce, steamed spare ribs with black beans, or chicken feet simmered slowly with black beans.