Good Eats Potato Starch is used to thicken sauces, gravies, soups, puddings, and pie fillings. Naturally gluten-free and flavorless, potato starch is also ideal for adding moistness and a fluffy texture to baked good. Potato starch tolerates higher temperatures than cornstarch, making it an excellent thickener for soups and stews. It adds moistness to any baked goods and is an essential ingredient in gluten free baking.