Bob's Red Mill Gluten Free Steel Cut Oats are pure. They are grown by over 200 farmer on clean, dedicated oat-growing fields. They plant only non-GMO "pedigreed" seed stock. Each farm delivery is sampled hundreds of times and tested with an R5 ELISA gluten test to ensure the absend of gluten. Advanced color-sorting removes undetected impurities. Roasting enhances that wholesome, robust flavor you expect. The oats are packaged in Bob's Red Mill's new, 100% gluten free facility and tested for gluten again to ensure their purity.