It is often necessary to peel and/or seed tomatoes for a recipe. Seeding tomatoes removes excess moisture and thereby also reduces the cooking time of some recipes. For example, if you don’t seed the tomatoes for Tomato Sauce, it will take at least 20 minutes longer than the 5 minutes indicated in the recipe to achieve its desired consistency. In other sauces, tomatoes are added just before serving. If not seeded and well drained, the sauce will be too thin.