Despised, ignored and even maligned, potato flour is the ugly duckling of gluten-free flours. Authors of cookbooks and writers of culinary Web sites describe it as having a heavy texture and a strong taste. Most say that they use very little of it. Some say to avoid it altogether. Only a few acknowledge the desirable attributes of potato flour and recommend its use. Cooking guides frequently dismiss potato flour in favor of potato starch flour (also called “potato starch”), yet people often refer to potato starch flour as “potato flour.” There are even brands of potato starch that bear the misleading label “Potato Flour.” Are there differences between the two, and should cooks avoid the ugly duckling?
The differences between potato flour and potato starch begin with the way they are made. To produce potato flour, entire potatoes are cooked, dried, and ground to a fine-textured powder. To make potato starch flour, only the starchy portion of the potato is processed. The resulting flours are quite different in nutritional value, taste, and cooking performance.
Nutritionally, there is no contest between potato flour and potato starch flour. The flour made from whole potatoes has 6.9 grams of protein and 5.9 grams of fiber per 100 grams of flour ¹. Potato starch has less than 0.1 gram of protein and 1.4 grams of fiber per 100 grams of product ². Furthermore, potato flour has significant amounts of several vitamins and minerals, while potato starch has only small amounts of these nutrients.
If nutritional value were the only criterion for choosing between the two flours, one would wonder why anyone would choose to use potato starch. Taste and texture may be additional considerations in selecting which flour to use, though. Potato flour retains potato flavor. That is a pleasant advantage in some applications, but when a recipe requires flour with a completely bland taste, potato starch may be the better choice. Furthermore, the texture of a baked product will differ depending on whether potato flour or potato starch is used. Both flours are hygroscopic; they attract moisture. Therefore, they help to maintain the moisture content in foods. However, while potato starch lightens the texture of a baked product, potato flour makes a baked product heavier.
The bland taste of potato starch and its ability to lighten texture are qualities that cause people to recommend it over potato flour, but it is the very flavor of the latter that makes it superior as a dusting flour for foods that are sautéed or fried. Chicken dusted with potato flour before frying combines the flavor of fried chicken and mashed potatoes. Eggplant, summer squash, and okra are other foods whose flavors are enhanced when they are coated with potato flour before sautéing or frying. In baked goods, the fact that potato flour adds flavor, weight, and “tooth” makes it more desirable than its bland, fluffy half sister when one is trying to duplicate qualities of whole grain breads.
When using potato flour in baked goods, the cook must keep in mind the flour's hygroscopic nature. Because potato flour soaks up more liquid than other flours do, the cook may have to add additional liquid to a recipe in which she has substituted potato flour for another flour. If she uses too much potato flour in a recipe and adds enough liquid to give the batter or dough proper consistency, the end product may be soggy. It is therefore advisable to substitute only small amounts of potato flour for other flours.
The ability of potato flour to absorb liquid and the fact that it has a potato flavor make it a good thickener for soups, stews, and meat dishes. Like wheat flour, potato flour should be mixed with cold water before it is stirred into hot liquid. Because potato flour clumps easily, it is important to mix only small amounts of cold liquid with it, stirring the mixture until it is smooth before adding more liquid.
Potato flour is nutritious and flavorful. Used in small amounts, it adds moisture to breads and other baked goods. It serves well as a thickener and as dusting flour for fried and sautéed foods. This little ugly duckling of the gluten-free flours is a swan in disguise.
i NutritionData, Nutrition Facts & Calorie Counter. http://www.nutritiondata.com/facts-001-02s0202.html
ii National Public Health Institute, Nutrition Unit. Fineli. Finnish food composition database. Release 5. Helsinki 2005. http://www.fineli.fi/food.php?foodid=162&lang=en