Precision Foods Cornstarch Bags - 25 Lb are useful as a thickener for sauces, gravies, and fruit pie fillings.  Corn Starch thickens very quickly and easily, forming a clear sauce after cooking.  It has roughly twice the thickening power of flour. If it is added to a cold mixture, it does not need to be prepared in any way before cooking and will dissolve as the mixture heats up.