Ingredient

Kidney beans

Kidney beans are large, firm, mealy beans that hold their shape through long cooking, which is why they are in chilli and in rice and peas. They are also the one common pulse where undercooking is not merely unpleasant, and that is worth knowing before anything else.

Why they must be boiled properly

Raw and undercooked red kidney beans contain a lectin that causes acute illness. It is destroyed by a period of vigorous boiling, and it is not reliably destroyed by low-temperature cooking — which is why a slow cooker on its own is specifically the wrong way to cook dried kidney beans from raw.

This is a real and documented hazard rather than a folk caution, and it is unusual among the pulses in a British kitchen. The practical consequence is simple: soak dried kidney beans, discard the soaking water, and boil them hard in fresh water before any slow or gentle cooking.

For the specific soaking and boiling times, consult the Food Standards Agency rather than a recipe. Those are safety figures and FoodHQ does not publish them.

Tinned kidney beans have already been through this and are ready to use straight from the tin. That is the great majority of kidney beans eaten in this country, and there is nothing to think about with them.

How they are used

• Chilli con carne, where they hold their shape through a long simmer while everything around them collapses.
• Rajma — the North Indian kidney bean curry, cooked with onion, tomato, ginger and garam masala until the sauce is thick and the beans are creamy. Arguably the best thing that happens to a kidney bean.
• Rice and peas — the Jamaican dish, where the "peas" are red kidney beans, cooked with coconut milk, thyme and scotch bonnet.
• Red beans and rice, the Louisiana dish, cooked long with pork until the beans break down into their own sauce.
• In a salad, from a tin, with red onion, parsley and a sharp dressing.
• In soups and stews, where their mealiness thickens the liquid.
• Mashed into a burger or a dip.

The kidney beans and their relatives

Red kidney bean

Large, dark red, firm, mealy. Holds shape well. The one in chilli.

White kidney bean / cannellini

The same species, white, softer and creamier. Italian, and used in soups and salads.

Borlotti / cranberry bean

Pink and speckled raw, browning when cooked. Creamier and sweeter than red kidney. Excellent in Italian soups.

Pinto bean

Mottled, softer, breaks down readily. The bean for refried beans.

Black bean

Smaller, denser, sweeter, and it produces a much better cooking liquid — see black beans.

Substituting

Any of these works in most recipes. Red kidney holds its shape best; pinto and borlotti break down most.

Cooking them from dried

Follow a food safety authority for the timings. This is the shape of the process.

1. Sort and rinse the dried beans.
2. Soak them in plenty of cold water for the period the authority specifies.
3. Drain and discard the soaking water, and rinse the beans.
4. Cover with fresh water and boil them vigorously — a genuine rolling boil, not a simmer — for the specified time.
5. Then reduce to a simmer and cook until tender, adding aromatics as you like.
6. Only after all of that should the beans go into a slow cooker, a stew or anything cooked gently.
7. Salt them towards the end, and add tomato, vinegar or other acid only once they are tender, since acid keeps the skins firm.

Common questions