How to Thicken Sauces with Gluten-Free Starches

Plain flour is commonly used to thicken sauces and gravies, but for people with celiac disease, gluten intolerance or wheat allergy, this gluten-containing thickener is off-limits. The good news is that there are a number of gluten-free alternatives that can be used to thicken sauces, stews and gravies. However, if you have always used plain flour to thicken your sauces and gravies, getting the hang of using these gluten-free alternatives may take some time. Below, we take a look at some starchy gluten-free sauce thickeners plus provide tips on how to use each. Note that the thickeners listed below have different strengths and weaknesses, so it may be a good idea to stock all of them in your pantry.

Corn starch

Use 1 tablespoon plus 1 teaspoon for every cup of liquid

Corn starch, or cornflour, is a great choice for thickening dairy-based sauces, gravies and puddings. When using corn starch, first mix it with cold water until it forms a smooth paste, and then add it to whatever you want to thicken. Note that corn starch does not stand up to freezing or prolonged cooking, and it loses its thickening potency when mixed with acidic liquids. What's more, if don't like to use genetically modified (GMO) ingredients in your cooking, corn starch is not the smartest choice, unless you go for a product that has been specifically labeled non-GMO. If you like to shop on Amazon, check out this non-GMO corn starch (note, though, that this corn starch has been produced in a facility that also processes wheat and gluten).

Arrowroot powder

Use 1 tablespoon plus 1 teaspoon for every cup of liquid
Compared with corn starch, arrowroot powder has many advantages: it thickens at a lower temperature, it has a more neutral flavor, its potency is not affected by acidic ingredients such as citrus juices, and it stands up to freezing. On the negative side, arrowroot powder is usually pricier than corn starch, and it is not a good thickener for dairy-based sauces. Look for arrowroot powder in Asian markets and health food stores, or order it online here.

Potato starch

Use 1 tablespoon for every cup of liquid
Not to be confused with potato flour which has a slightly grainy texture, potato starch makes an ideal gluten-free thickener for savory sauces and gravies that don't need to be boiled for a long time (overheating a sauce thickened with potato starch will thin it out). Like cornstarch, potato starch has to be dissolved in a little bit of water before using it as a thickener. Potato starch is readily available at supermarkets across the country.

Tapioca starch

Use 1 tablespoon plus 1 teaspoon for every cup of liquid
Tapioca starch refers to a fine ground powder made from the dried root of the cassava plant which grows in the tropics. The great thing about this gluten-free sauce thickener is that it remains stable when frozen. It also works quickly, so it's a good choice if you want to correct a sauce just before serving it. On the downside, finding tapioca starch in the stores can be challenging. Coarsely ground tapioca or cassava flour and instant tapioca are much easier to find; however, they don't dissolve completely and can leave small but noticeable gelatinous blobs in your sauce or gravy.