In the most basic terms, a raisin is simply a dried grape. All raisins can be stored tightly wrapped at room temperature for several months. For prolonged storage (up to a year), they should be refrigerated in a tightly sealed plastic bag. Raisins can be eaten out of hand, as well as used in a variety of baked goods and in cooked and raw dishes. They have a high natural sugar content, contain a variety of vitamins and minerals and are especially rich in iron.