A kidney bean is a type of large, reddish-brown bean shaped like a human kidney, with one side curved outward and the other curved inward. The beans get their name from this distinctive kidney shape, which you can see clearly when you look at one sitting on a plate.

Kidney beans are common in many cuisines around the world. In the United States, they're a key ingredient in chili con carne, that hearty stew with meat, tomatoes, and spices. In Latin America, they appear in dishes like frijoles (beans served alongside rice). In India, a spiced kidney bean curry called rajma is popular comfort food.

The beans grow in pods on bushy plants, and farmers harvest them when the pods dry out. You'll usually buy kidney beans either dried (where they look wrinkled and hard) or in cans (where they're already cooked and ready to eat). If you cook dried kidney beans, you need to soak and boil them thoroughly, because raw kidney beans contain a toxin that proper cooking destroys.

Their mild, slightly sweet flavor and firm texture make kidney beans filling and versatile. They're packed with protein and fiber, which is why people have been growing and eating them for thousands of years, long before anyone knew what protein and fiber even were.