Rinse beans thoroughly, and then sort them.
Warm water should be added to the beans, covering them by 2 inches in a bowl or pot. Allow to soak overnight. This step is optional and can be skipped if time is tight. If you are not soaking, add another cup of water to step 4.
Drain the beans and put them in a slow cooker.
Add 6 cups water, salt and pepper to the mixture. If you are vegetarian, use a bay leaf.
Cook beans on low for 8 hours, or high for 5 hours. Cover beans and continue cooking until tender. It may take longer depending on the age of your beans and how slow you cook them.
If necessary, taste and adjust salt.