Cover beans with ample hot water and allow to stand overnight.
Fill a Dutch oven 1/2 full with water and bring to a boil over high heat. Add salt pork, and allow to boil for 5 minutes, then remove. Pour out water.
Drain water from beans and place them into Dutch oven. Pour in 10 cups of water, then bring to a boil over high heat. Boil for 15 minutes, skimming and discarding the foam that forms on top. Stir in saffron, salt pork, and diced ham; simmer for 5 minutes. Add the chorizo and morcilla sausages, and cook for 5 minutes more. Skim any foam that forms on top.
Reduce heat to low, add bay leaf, cover, and simmer until the beans are tender, 2 to 3 hours, adding water if needed to keep beans moist. Allow beans to stand for 20 minutes off of the heat before serving.
