This delicious slow cooker bean and bacon soup recipe is the perfect winter comfort food. The recipe is inexpensive, thick, rich, and flavorful, with the best texture. Serve with some crusty bread or toasted garlic bread and a green salad for a wonderful meal. Before cooking dried beans, always sort over the beans. There may be sticks, twigs, or stones mixed among them. After sorting, rinse the beans well to remove any dust or dirt and drain them. You can soak the beans overnight to help remove the sugars from the beans that can cause intestinal gas. Discard the soaking water; rinse and drain the beans again, and use them in the recipe. The secret to the best bean soup is to add salt until the flavor blooms. But do this just before you serve the soup. Don't add too much salt at the start of cooking time, since the bacon is salty. Tomatoes are added at the end of the cooking time because the acid in tomatoes prevents beans from softening, even when they're cooked for hours. If you like, you can mash some of the beans for a thicker soup before adding the tomatoes.