How to Substitute Cornstarch for Flour in Recipes

Cornstarch

Verywell / Alexandra Shytsman

Lots of recipes use flour as a thickener, a coating, or another ingredient. You might want to use an alternative to flour. Flour that won't work for you if you're on the gluten-free diet because you have celiac disease or non-celiac gluten sensitivity.

While pure cornstarch is gluten-free (it's just made of corn), some brands aren't considered safe on the gluten-free diet so choose a safe brand of gluten-free cornstarch. Here's a guide to substituting cornstarch for flour in recipes.

Substitute Cornstarch for Flour

It's easy to substitute cornstarch for flour when your recipe calls for a thickener (as in gravy, sauce or pie) or a coating for fried foods. Whether you simply don't have flour on hand or you are looking for gluten-free alternatives, cornstarch has a very similar effect in these cooking applications. However, you should be aware that you can't use cornstarch as a substitute for flour in baked goods.

Thickening Gravy, Sauces, or Pie Fillings

Cornstarch works remarkably well as a thickener in sauces, gravy, and pie fillings, and some prefer it to flour. You won't be able to taste the cornstarch the way you sometimes can taste the flour. Be aware that these foods will be more translucent. This occurs because cornstarch is pure starch, while flour contains some protein.

You can't use cornstarch as a tablespoon-for-tablespoon substitute for flour. Generally speaking, you should use 1 tablespoon of cornstarch for each 1 1/2 to 2 cups of sauce/gravy of medium thickness.

Some things to remember when using cornstarch as a thickener in recipes:

  • Bring the mixture to a full boil for 1 minute, which allows the starch granules to swell to their maximum. Reduce heat as it thickens. Overcooking can cause mixtures to thin when they cool.
  • Cook over medium-low to medium heat, because high heat can cause lumping.
  • Stir gently while cooking, as stirring vigorously can break down your mixture. If you need to add more ingredients, remove the pot from the heat and stir them in quickly and gently.
  • You might want to avoid freezing any sauces or gravy you make with cornstarch since they won't freeze well. They turn spongy.

Cornstarch vs. Flour

Use half as much cornstarch as you would flour. For example, if the recipe calls for 2 tablespoons of flour, use 1 tablespoon of cornstarch. If the recipe calls for 1/4 cup of flour, use 1/8 cup of cornstarch. (The same is true for other starches, such as arrowroot starch, potato starch, and tapioca.)

Also Keep in Mind

Don't add the cornstarch directly—it will clump up and form lumps in your sauce that will be very difficult to dissolve. To avoid this problem, mix the cornstarch with a little cold water (1 tablespoon water to 1 tablespoon cornstarch) until it's dissolved. Then pour the water/starch mixture (known as a slurry) into what you're cooking. Make sure the water you use is cold, and keep stirring as the mixture begins to thicken.

Cornstarch isn't as effective as flour when thickening acidic sauces. It won't work well with those made with tomatoes, vinegar, or lemon juice. Cornstarch also isn't as effective as flour when thickening sauces made with fat, such as butter or egg yolks.

If you have too little liquid in your mixture, there may not be enough for the starch granules to absorb. This is also the case when you have more sugar than liquid, in which case you may need to add more liquid for the mixture to be firmer.

Fried Dishes

You easily can use cornstarch instead of flour as a coating for fried chicken, fried fish, or other fried dishes. Cornstarch will create a crisper coating that will hold up to sauces better and will absorb less of the frying oil (leading to a lower-fat meal).

Here are some tips for frying with cornstarch:

  • Consider a 50/50-blend of cornstarch and gluten-free flour—this will
    give you a coating that's closer to wheat flour-breaded fried chicken.
  • Make sure you have a light, even coating of cornstarch on the food you're frying. Heavier coatings can get gummy.

A Word From Verywell

When cooking gluten-free, you may be able to continue to enjoy some of your favorite sauces by learning how to use cornstarch and other gluten-free thickeners. While mastering the art of substitutions can take some trial and error, it can also inspire creativity in the kitchen, leading you to also whip up new creations of your very own.

8 Sources
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Rai S, Kaur A, Chopra CS. Gluten-free products for celiac susceptible peopleFront Nutr. 2018;5:116. doi:10.3389/fnut.2018.00116

  2. Bob's Red Mill. Baking with cornstarch: Everything you need to know.

  3. Denver Post. Cornstarch a good way to thicken gravy lightly.

  4. Cook's Info. Thickeners.

  5. Taste of Home. Cornstarch vs. flour vs. arrowroot - when should you use which thickener?

  6. Bon Appetit. Cornstarch is a powerful tool that must be used responsibly.

  7. The BC Cook Articulation Committee. Types of thickening agents.

  8. Bon Appetit. 4 brilliant ways to cook with cornstarch.

By Nancy Lapid
Nancy Ehrlich Lapid is an expert on celiac disease and serves as the Editor-in-Charge at Reuters Health.