Gordon Ramsay gave a recipe involving dried haricot or cannellini beans in the Times the other week. (I cannot find it online.) Soak the beans overnight, he advised; cover them with fresh water, fast-boil them for 10 minutes, turn down the heat and simmer for an hour, or until soft. He did not explain these instructions. What is the point of them?
I have found it difficult to get authoritative information about the cooking of dried legumes. But I have come to a few conclusions.
Salt. Most cookery writers tell you not to add salt to the water in which beans or pulses are cooking. It toughens the skins; it inhibits softening. I have found that dried beans will soften in salted water -- in the water that comes from my taps in North London, anyway. However, I thought that I should test this finding again.
I put two lots of beans -- they were organic haricots -- on the hob: one in unsalted, the other in salted, water. I tasted them after an hour. Both were cooked; but they had different textures. Behaving exactly according to the observations of Harold McGee in his great book, the salted beans had a mealy texture, while the unsalted ones were creamy. I shall leave the cooking water unsalted from now on, and season the beans when they are cooked.
Soaking. I set soaked beans and unsoaked ones to cook. The soaked beans were ready earlier; and, again, they had a more pleasing texture.
Fast boiling. The theory is that 10 minutes of fast boiling eliminates substances called protease inhibitors, which can block the digestion of proteins. However, protease inhibitors have beneficial effects too. My researches took me to Dr Claire Domoney of the department of metabolic biology at the John Innes Centre; she told me that protease inhibitors were, on balance, good things, and were in any event too stable to be affected by a short period of boiling on a domestic hob.
Red kidney beans. These contain lectins, which can cause stomach upsets. You should soak them (the Food Standards Agency recommends that you do so for 12 hours), fast-boil them for 10 minutes, and make sure that they are properly cooked.
Cooking the beans. Soak the haricot, cannellini or kidney beans -- I use filtered water, because hard water does toughen the skins, I find -- for five hours, or longer. Drain, cover in fresh, filtered water, bring to the boil, and simmer. Cooking times vary from 45 minutes to two and a half hours, or longer.
About 50 g for each person makes a decent portion as a side dish. I might allow for 75 g a person in a pork and bean stew or cassoulet. You can add an onion to the water; I usually throw in a garlic clove or two.
Drain the beans, retaining the water. Assuming you've cooked 200 g of beans: soften a clove of garlic in a tbsp of olive oil. Add a dstsp of tomato paste, the beans (with any garlic you have cooked with them), salt and pepper, and a tbsp or two of cooking liquid, to give a stew-like consistency. Simmer for 10 minutes. You can use the left-over cooking liquid for soups.