You want to serve up sauces with the correct viscosity to cling to the intended food, not run everywhere. Here are some tips on how to thicken sauce with cornstarch and flour—items likely already in your pantry so that you don’t have to run to the store.
How to Thicken Sauce with Flour
To use flour as a thickening agent:
How to Thicken Sauce with Cornstarch
Thickening a sauce with cornstarch is very similar to using flour, but you need different quantities: Test Kitchen Tip: Be careful not to overcook cornstarch-thickened sauces. They can break down when overcooked (the starch loses its thickening properties when cooked too long).
Substituting Cornstarch for Flour as a Gluten-Free Alternative
If you have someone in the family with an allergy restriction, you may need a gluten-free thickener for your soup recipe. It’s important to note that cornstarch has twice the thickening power of flour. If you need to substitute cornstarch in a gravy recipe that calls for ¼ cup (four tablespoons) flour, you would only need to use two tablespoons cornstarch. If you’re substituting flour for cornstarch to thicken the sauce in your recipe, substitute two tablespoons all-purpose flour for every one tablespoon cornstarch. Note: Our Test Kitchen does not recommend freezing cornstarch thickened mixtures as the freezing process breaks down the starch thickening properties.
Other Thickening Agents
Flour and cornstarch aren’t your only options to use as a food thickener. When it comes to thickening soup and other sauce-based recipes, you can make a roux (a mixture of flour and fat). This is common for creamy soups such as baked potato soup and sauces such as macaroni and cheese. (Get the full instructions on how to make roux here.) Depending on your recipe, you can use eggs, a roux, or a puree of ingredients for a liquid thickener. The soup thickener depends on the recipe because some thickening agents can affect the soup’s flavor. Put those thickening skills to good use by making chicken marsala for dinner or a delicious turkey gravy for your Thanksgiving feast. You can also make some sweet additions to your menus with a raspberry-rhubarb waffle topper or lemon curd.
