Cornstarch

Cornstarch is a fine, flavorless white powder used almost entirely as a thickener, whisked into cold water or broth to make a slurry before being stirred into simmering sauces, gravies, stir-fry sauces and pie fillings to give them body and a glossy sheen. It's also dusted onto meat or tofu before frying to create a light, crisp coating, and it shows up in some custards and puddings as the setting agent. Because it thickens with a clear, glossy finish rather than the cloudier result flour gives, it's the preferred choice for fruit pie fillings and Asian-style stir-fry sauces.

Keep it sealed in a cool, dry pantry, where it lasts indefinitely as long as moisture stays out, since clumping is the main sign it's absorbed humidity. A cup weighs in at 381 calories per 100 grams and 91.3 grams of carbohydrate, but with only 0.26 grams of protein and virtually no fat, cornstarch functions purely as a cooking tool rather than a nutrient source, used in small tablespoon amounts where its calorie and carbohydrate contribution to the finished dish is minor. Always mixing it with cold liquid first, rather than adding the dry powder directly to a hot pan, prevents it from seizing into lumps.