The kidney bean is a medium-sized variety of the common bean (Phaseolus vulgaris) with dark red skin. The kidney bean is also known as the red bean, although this usage can cause confusion with the azuki bean.

The raw beans must be boiled for at least ten minutes before they are edible. The boiling degrades a toxic compound - the lectin phytohaemagglutinin - found in the bean which would otherwise cause severe gastric upset. Kidney beans may be bought uncooked, or pre-cooked and canned with water and salt, and sometimes also sugar.

External links

• Plant lectins