Black bean

Black beans are the small, oval, shiny black seeds of a dark-seeded variety of the common bean. The pods grow on bush or climbing plants, and each pod contains five or six seeds, which are harvested dry for storage.

Cooked, they keep their shape well and have a dense, creamy interior with a mild earthy sweetness and a slightly mushroom-like depth. Their cooking liquid turns inky dark.

They are sold dried, canned, as flour and as pre-cooked refried beans. Black soybeans are a different species and should not be confused with them.

The common bean, Phaseolus vulgaris, was domesticated independently in Mesoamerica and the Andes, roughly eight thousand years ago or more. Black seeded types are especially associated with Mesoamerica, where they were an essential partner of maize and squash.

After the Columbian exchange beans spread to Europe, Africa and Asia, but black beans remained most prominent in Latin America and the Caribbean.

The name turtle bean is said to refer to the hard, shell-like coat of the dry seed. The word bean itself comes from Old English, from Germanic roots shared with Dutch and German.

In pre-Columbian Mesoamerica, beans, maize and squash formed an agricultural trio that supplied balanced nutrition, and black beans were among the favoured types in southern Mexico, Guatemala and the Maya area.

Spanish and Portuguese colonisers brought beans to their other colonies, and African and indigenous traditions blended in dishes such as Brazil's feijoada, Cuba's moros y cristianos, and Mexico's frijoles de la olla.

In the 20th century black beans became a core staple of Cuban, Venezuelan and Brazilian diets, and spread through migration to the United States, where they entered vegetarian and Tex-Mex cooking. Breeding programmes in countries like the United States and Brazil developed higher-yielding, disease-resistant black bean varieties.

Beans also had political and economic importance: price controls and food policies in Latin American countries have often focused on keeping beans affordable for poorer households.

Dried black beans are soaked and simmered until tender, then served whole in soups, stews and rice dishes, mashed into refried beans, or blended into dips and veggie burgers. They are essential in Brazilian feijoada, Cuban black bean soup and Mexican tacos and burritos.

Their cooked liquid is used to thicken dishes. Flour made from black beans is used in gluten-free baking and as a protein addition, and black bean paste is used in some desserts, and brownies.

Sprouted black beans are occasionally eaten too, though they require cooking.

Black beans provide plant protein, fibre, folate, iron and magnesium, and their dark seed coat contains anthocyanin pigments with antioxidant activity. Regular intake of legumes is associated in population studies with lower blood cholesterol and better blood sugar control, and a lower risk of heart disease.

The resistant starch and fibre feed gut bacteria. Evidence for specific effects of black beans, as opposed to legumes in general, is smaller.