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.
The agricultural writer Jia Sixie (c.ad 540) was the first author to explain how these black beans are prepared, in a work which had the engaging title ‘Essential Skills for the Daily Life of the People’ (Qimin Yaoshu).
Since the soya bean commonly occurs in a black form, as well as in other colours such as light brown, it is natural to think that it is this black form which is fermented. However, it is not necessarily so. Beans lighter in colour may be used and will darken as a result of the fermentation.
Fermented black beans are prepared in many regional varieties. In most processes the raw beans are salted and allowed to soften under the influence of their own enzymes at a high temperature; enzyme action also darkens the colour. Some varieties are made by a wet pickling process using brine, vinegar, or wine. The end product, which is always salted, may be had in cans or dry packs and keeps well.
Fermented black beans have a strong flavour, but the black bean sauce prepared from them is delicate.
Alan Davidson was a distinguished author and publisher, and one of the world's best-known writers on fish and fish cookery. In 1975 he retired early from the diplomatic service—after serving in, among other places, Washington, Egypt, Tunisia, and Laos, where he was British Ambassador—to pursue a fruitful second career as a food historian and food writer extraordinaire. Among his popular books are Seafood of South-East Asia, North Atlantic Seafood, and Mediterranean Seafood. In 2003, shortly before his death, he was awarded the Erasmus Prize for his contribution to European culture.
So, Yan-Kit (1992), Classic Food of China, London: Macmillan.
