When using rhubarb in a baking recipe, you usually don't need to peel it. The bright red or pink stalks are what you'll use in your cooking, while the leaves should be removed and discarded since they're not edible. Rhubarb skin is thin and tender when cooked, so there's usually no need to peel it. However, any tough or fibrous strings on the surface, should be removed with a vegetable peeler.