Yes, there will be liquid left in the pot after the beans are done but that is actually a good thing. As you mix the beans, some will start to break and mix with the liquid, which will give the side dish a creamy consistency. If you don't want your side to have too much liquid, you can also use a slotted spoon and strain off some of the liquid. Keep in mind that many people do prefer the black eyed peas to have some of this flavorful cooking liquid with the beans. When storing the cooked beans, store them with the liquids. They will be even better the next day.