Place the beans in a large heavy pot with a lid. Fill the pot with enough water to cover the beans by 2 inches (5 cm) and bring to a boil over medium-high heat. Skim off any foam that comes up to the surface.
Lower the heat to keep the beans at a gentle simmer. Add 1 teaspoon salt if the beans have been soaked in salted water. If not, add 2 to 3 teaspoons depending on your love of salt.