Beans and Pulses · FFET10408
Black soybean (heidou)
A black-coated soybean with a green or yellow interior, eaten as food and used to make douchi and soy sauce.
Soybeans and the other pulses: mung, adzuki and broad beans.
Here, black soybean means a soybean with a black seed coat and a green or yellow interior, distinct from black turtle beans and urad beans, which may also be called black beans. Historical writing also calls it wudou and records its use as food and for making douchi.
What
Here, heidou refers to soybeans with black seed coats, also called black soybeans or wudou. The name can also refer to other beans, so black turtle beans and urad beans should be distinguished from these soybeans.2,3
When
An old agricultural text distinguishes white and black soybeans, while a passage quoted in another historical work records soybean gathering in the ninth month. These accounts do not establish when black soybeans originated, and the gathering reference concerns soybeans generally.1,2
Where
Historical writing records soybeans growing on level ground near Mount Tai and describes black and white soybeans being grown widely. These historical accounts do not establish today's main black soybean growing areas.2
How
An old agricultural text describes spring sowing for soybeans, while another historical work describes sowing wudou around the summer solstice and flowering in autumn. Wudou is eaten as food and used to make douchi.1,2
Why
Black soybeans have black seed coats with green or yellow interiors; the dark exterior does not mean the bean is black inside.3
Impact and influence
Black soybeans serve as ingredients for douchi and soy sauce.3