Potato starch and potato flour are often confused for each other. In many places, you will see the two names used interchangeably and many people believe that the terms refer to the same thing. Potato starch and potato flour are two different products that have different properties and applications. Both do come from potatoes and neither contains gluten.
Beyond those two similarities, they have some major differences. You should take their similarities and differences into account before you choose one or the other for your application. Here is a closer look at how potato starch and potato flour compare.
How does potato starch differ from potato flour?
The first major difference between potato starch and potato flour is the nature of the two products. Potato starch is made from starch that has been extracted from potatoes and then refined. It consists of only the starch part of the potato and the potatoes used to make it are chosen for their high starch content. In comparison, potato flour consists of the whole potato that has been dehydrated and then powdered.
Potato Starch 
Potato Flour
Potato starch has a completely neutral taste since it is only the starch from the potato. Potato flour has the potato flavor since it contains everything that is in a whole potato.
Nutritional value is another area where there is a major difference between potato starch and potato flour. Potato starch is almost nutritionally void, which means that it has no vitamins and minerals though it does have a high carbohydrate value. Potato flour contains a range of vitamins and minerals while also being a good source of fiber.
Potato starch and potato flour differ in terms of appearance as well. Potato starch is an extremely fine powder that looks and functions a lot like cornstarch. Potato flour is fine as well, but not as fine as potato starch. It is closer in texture to wheat flour. Potato flour is completely white, while potato flour has the same pale yellow color as the inside of a potato.
If your recipe calls for one, can you use the other?
Potato starch can work as a substitute for potato flour if you plan to use it as a thickener and don’t care about the nutritional value. It won’t affect the taste of the final dish. In addition, you can use potato starch as a potato flour substitute when baking some dishes though it won’t provide all of potato flour’s benefits such as the retention of moisture.
Potato flour can work as a substitute for potato starch if you don’t mind the potato flavor. If you need a thickener with a neutral flavor, it won’t work.
How should you use potato starch and potato flour?
Use potato starch as a neutral thickener in the same way that you would use cornstarch. It has a few advantages over cornstarch including the fact that it can stand up to higher temperatures without breaking down. It also gives it a silkier, glossier consistency. In baked goods, potato starch can help to make baked goods bulkier.
Use potato flour in dishes and baked goods where you want the potato flavor as well as the nutrients from the potato. Potato flour can also be used in cake batters and bread doughs to help them retain moisture.