Place the fava beans in a large bowl, as they will expand. Add twice as much water as beans. If the water level drops, add more. Soak for about 36 hours (two days and one night).

Drain the beans and rinse them well. (You should have rinsed them before soaking, too.) Place the beans in a large pot and add twice as much water as beans, along with 1 teaspoon baking soda.

Bring to a boil and simmer until the beans turn brown and are tender. Taste or check with a fork to see if they are done.