Bob's Red Mill Potato Starch is made from top quality high starch potatoes by an natural water and filtration process. It is excellent as a thickener for making gravies sauces soups or stews. Our Potato Starch is also a terrific ingredient for gluten-free baking as it produces a tender moist crumb. Your Can See Our Quality! Bob's Red Mill products labeled Gluten Free are batch tested in our quality control laboratory. We use an ELISA Gluten Assay test to determine if a product is gluten free.