Kidney beans are hearty, protein-rich legumes that can be purchased as either canned or dried food. Although canned kidney beans are more convenient to use, many cooks believe that dried kidney beans are a more flavorful and economical addition to chilies, salads and soups. When choosing dried beans, look for those that are uniform in size, shape and color. Avoid purchasing any beans that appear to be damaged or look like they might have been exposed to moisture. If cooking time is an issue, and you would prefer to buy canned beans, try to find an organic product with a label that clearly indicates that the can has not been lined with an epoxy called bisphenol.
Farms in countries all over the world grow kidney beans for the commercial market. Unless the country of origin and the date of production are clearly indicated on the package, you will have no way of knowing where your beans come from or how old they are. These two variables can affect the way that your beans will taste after they have been prepared. For reasons of flavor and safety, you should take a few simple cooking precautions.
Canned kidney beans typically are high in salt. When you check the label for the expiration date, check it for the salt content as well. Try to choose beans that have the lowest amount of additives. To get rid of the salt, rinse your canned beans in cold water before you use them. This is especially important if you are on a restricted diet.
To eliminate surface dirt and pebbles, wash dried kidney beans carefully. Discard any that look wrinkled or deformed, then soak the good beans for at least five hours or overnight. If possible, use soft water instead of hard water. Hard water, either from the tap or a bottle, can make the beans tough and less flavorful.
After your beans have been soaked, rinse and drain them in a colander. Prior to cooking, boil the beans in fresh water for at least 10 minutes. Again, soft water is best. Make sure that the beans are completely cooked before you serve them, especially if you are using a slow cooker.
Red kidney beans contain less phytohaemagglutnin or kidney bean lectin than white kidney beans. Bean lectins are toxic unless deactivated during the cooking process. If you are not using canned beans, make sure that your dried beans have been properly prepared. Undercooked beans can be more poisonous than raw beans, which is why it is so important to wash, soak and cook them thoroughly.