Produced from the potato, potato starch and potato flour have notable differences when cooking, regarding function, taste and nutritional value. Confusing the two potato products, a common mistake by cooks, can result in a recipe gone wrong.
The production of potato starch is a process of refining, washing, rasping (high-speed machinery used to release the starch from the tuber cells from the interior of the potato), extracting the starch from the potato, and then refining the starch once again. To create potato flour, manufacturers dehydrate the potatoes then crush and grind them.
Potato starch resembles and feels much like cornstarch, powder-like with a neutral flavor. Potato flour is heavier in weight than the starch, with a consistency resembling flour made from wheat. It has a potato taste.
Potato starch is used as a thickening agent, while potato flour is used for baking and as an addition to potato dishes, such as a potato soup.
Thicken soups, gravies and sauces with potato starch in place of cornstarch or flour. Rolls, breads and some cakes can be made entirely with potato flour or with a mixture of potato flour and flour made from wheat.
Both potato starch and potato flour are gluten-free foods (proteins derived from wheat products), making them an ideal substitute for those with an intolerance for gluten. However, the starch has little nutritional value, compared to potato flour.