Many traditional dishes from around the world revolve around filling a stoneware crock with beans and flavoring ingredients, then letting them slow-cook gently on a hearth or in the ashes of a dying fire. Countertop slow cookers replicate that process with a small electric element and multiple settings, enabling modern cooks to take advantage of the same long, slow cooking time. Simmering your beans together with soup bones and other aromatic ingredients is one way to infuse your beans -- and anything made with them -- with rich, well-balanced flavors.
Soak your beans overnight in a bowl or sink with enough cold water to cover them to a depth of 2 inches.
Place your soup bones in the bottom of your slow cooker, and surround them with coarsely chopped onions, garlic, bay leaves or other aromatic ingredients as desired.
Pour your soaked beans in around the soup bones. Pour in enough water or broth -- either meat or vegetable broth -- to cover the beans to a depth of 1/4 inch. Little water will evaporate, so you don't need much extra.
Simmer the beans for eight to 10 hours on your cooker's "Low" setting, or until they're tender but not yet falling apart. Serve the beans in their cooking liquid, or drain them and refrigerate or freeze them for later use.
Chicken or beef bones can give the beans a richer flavor if they're roasted in a hot oven first. Ham bones and other pork bones don't benefit from roasting, so add them to the pot just as they are. Ham bones are the most common choice for this cooking method because the flavors of beans and ham are so complementary.
Some beans, especially kidney beans and fava beans, contain toxins that are destroyed by the heat of cooking. Slow cookers don't get hot enough to reliably neutralize these toxins, so those beans should be boiled on the stovetop for a minimum of 10 minutes before they're drained and added to the slow cooker.