Potato starch is essential if you are on a gluten-free diet or if you want a resistant starch that can help you to lose weight. Use it to thicken everything from gravies to pie filling. Can’t find potato starch or need an immediate alternative? Let’s review your best potato starch substitute, as well as a few in a pinch solutions.
Your best bet: Tapioca starch
Tapioca starch is derived from a root, just like potato starch. It is made from the manioc root, which is also known to West Indians as cassava. The root is dried and pounded until it is made into a fine-textured flour. Tapioca starch is also called tapioca flour. Like potato starch, tapioca starch can be used in place of wheat flour.
When using tapioca starch as a potato starch substitute for thickening, note that its ability to thicken is slightly less than that of potato starch. You will want to use roughly twice the amount that your recipe requires for potato starch. Make a slurry by combining the tapioca with water and adding it to the dish. Note that tapioca does not handle acidic liquids well and may lose its thickening ability when combined with them. It also acts very quickly but does not handle long cooking very well. Use it at the last minute rather than early on in the cooking process.
Because tapioca starch is slightly lighter than potato starch, note that you will need to use more to achieve a similar degree of density. Add an extra 1/4 cup for every two cups of potato starch that your recipe requires.
A decent second choice: Arrowroot
Arrowroot is another starch that is similar to root starches and just as effective for thickening. Arrowroot comes from a variety of plants that belong to the Marantaceae family. In some cases, tapioca is sold as arrowroot. Arrowroot is made by grinding the fibrous roots and separating them. The pulp that makes up the arrowroot rhizome is then dried and powdered to make arrowroot powder. It is an excellent thickener with several qualities that set it apart from other popular thickeners, such as the fact that it does not break down in acidic liquids.
You can also use it in place of wheat flour for gluten-free baking. It can actually be an improvement on wheat flour in that it makes cakes and cookies lighter.
When using arrowroot in place of potato starch as a thickener or in baking, use the same amount that your recipe requires for potato starch.
In a pinch: Corn starch
Corn starch is arguably the most popular thickener. It is both readily available and easy to use. Corn starch is a grain thickener as opposed to a root thickener. It is a carbohydrate that comes from the endosperm of the corn kernel. It is versatile in that like the other thickeners on this list, it has a neutral taste and liquids thickened with it have a glossy finish. Unlike potato starch and the other starches on this list, it can be used at a high heat. Its only real drawback is that it tends to break down in acidic liquids. When used in acidic sauces or pie fillings, it will not thicken and may give the liquid a chalky mouth-feel.
Use corn starch as a 1:1 substitute in place of potato starch. Make a slurry by mixing it with the same amount of water that your recipe requires for a potato starch slurry.
Other alternatives
Flour is another classic thickener that can stand up to both acidic liquids and long cooking times. You can use it in both sweet and savory dishes as a thickener. The drawback is that it can make thickened liquids cloudy and matte rather than clear and shiny.