Cooking in a slow cooker is both similar to and different from conventional cooking. The significant change required to your cooking technique is not to lift the lid before the end of the specified cooking time, unless instructed to in a recipe. Lifting the lid breaks the seal and lowers the temperature. Getting used to not lifting the lid is challenging when first using a slow cooker, as a cook’s natural inclination is to sniff, stir and taste, but you must resist. If you do lift the lid, however, add 15 minutes to the total cooking time.