Kuzu is an effective plant-based binding agent made from the starch of the kuzu plant. It is widely used in Japan for soups, sauces, and (hot) desserts. The good thing about kuzu is that it does not affect the flavor of a dish. Unlike cornstarch, kuzu can also be used in sour dishes. Plus, it's gluten-free and vegetarian! White kuzu is washed and filtered, so the taste is neutral and the binding power is slightly stronger than that of gray kuzu.