MAKES ABOUT 6 CUPS/1.2 KG COOKED BEANS
White beans need to boil gently so that they don’t break. “Use little water so they don’t dance and fly though the water,” advises the woman in my neighborhood market, from whom I buy most of my dried and cooked beans. “Keep the heat very low. And season with salt only at the end.”
Rinse the beans with cold water. Place them in a large bowl, cover with plenty of cold water, place in a cool spot, and soak for 8 hours. Drain, rinse away any yeasty or fermenting odors, and drain again.
In a large, heavy pot, add the beans, onion, garlic, and bay leaf; cover with no more than 1% inches/4 cm cold water (about two finger spaces); and put over high heat. Just as it begins to show signs of boiling, skim off the foam, reduce the heat to low, and add the olive oil. Cover the pot and very gently boil until tender, about 2 hours, though it depends on the type, size, and age of the beans. Gently shake (don’t stir) the pot from time to time. If the pot needs more water during cooking, add cold water. Season with salt at the end of cooking.
Remove the pot from the heat and leave the beans in the water until ready to use. Drain and discard the onion, garlic, and bay leaf.