Black Beans

black beans a term which may refer either (a) to a kind of haricot bean, namely the Mexican black beans which are widely eaten in Latin America and give their name to black bean soup, or (b) in the sense treated here, to black soya beans, fermented and preserved by salting.

The latter, known as chi to the Chinese, have been an important relish in their cuisine since the Han dynasty (beginning in the 2nd century bc). Yan-Kit So (1992) remarks on this, noting that the evidence is supplied by inscriptions discovered in 1972 on bamboo slips in a Han tomb in Hunan province. She also explains that:

Black beans are also made from cooked soy beans which, halfway through their hydrolytic decomposition, are dried at a very high temperature and become darkened as a result of oxidation.