Potato starch
A fine white thickener made from potatoes that sets sauces and batters clear and glossy.
In German-speaking countries potato starch is on every supermarket shelf, often sold simply as starch or potato flour. In English-speaking countries it is less common and is more often found in Asian grocers, Eastern European shops, health food stores or by mail order.
Substitute:
Cornstarch thickens in much the same way but turns slightly cloudier and needs a little more. As a coating it is less crisp.