Clean the beans and soak them in 6 cups of water for 4-8 hours –or try the quick-soak method: boil them for one minute, then let them soak for 1 hour.
Drain the soaking water and add 6 more cups of fresh water.
Add the onion and Bacon Up bacon grease, then cover and simmer for 1-2 hours over medium-low heat until the beans are tender.
Add the salt when they are about 15 minutes from finished. (Optional: If you like a little more heat, add your favorite hot sauce to taste. Fresh cilantro also makes a flavorful garnish, if you wish to add.)