Potato Starch, 4 ounce bag (113 grams). Potato Starch is a gluten free thickener that is useful for thickening soups, stews, gravy and sauces. Potato Starch is commonly used to replace cornstarch in baking recipes. Potato Starch will provide a moist and soft texture in pastries like sponge cake. Refrigerate or Freeze After opening to increase shelf life.