Rinse the beans in water and remove any small stones, pieces of dirt, or bad beans.
Place the beans in a large bowl or saucepan and cover with water. Leave overnight.
The next day, combine all the ingredients in the crockpot. Remove any floating beans. Cover, and cook on HIGH for 4 hours and on LOW for 2 hours.
Uncover, and remove extra liquid. Leave enough liquid to reach the desired consistency when the beans are mashed. (We like our beans somewhere between the very-liquidy restaurant style beans, and the canned version of refried beans.)
Mash beans with a potato masher to desired consistency.
Serve warm. Store in air-tight containers in the refrigerator and use within 2 weeks, or freeze in ziplock bags for later use.