Can I Substitute Cornstarch for Flour?

It’s easy to substitute cornstarch with flour when your recipe calls for it as an ingredient. Whether you need to add it in sauce, gravy, pie or as a coating for fried foods, flour works similarly to cornstarch in these cooking applications.

Yes, you can substitute cornstarch with flour. However, how much you use and how to use it and the outcome differs significantly. In most cases, while a recipe calls for 1 tablespoon of cornstarch, you’ll need to substitute it with 2 tablespoons of flour.

So, you’ll generally need twice as much flour as cornstarch for thickening purposes. The only shortcoming is that you can’t substitute cornstarch for flour in baking.

Can I Substitute Cornstarch for Flour?

Cornstarch vs Flour

Unlike flour, cornstarch appears to be more white and in a more refined texture. While flour is a primary ingredient in baking, cornstarch is only used for specific baking purposes, like in baking shortbread recipes. 

This is because cornstarch only contains starch, while flour contains starch, protein and fiber. It is the protein in gluten that aids the elasticity and chewable characteristics in flour-baked products.  

While flour contains gluten, cornstarch is gluten-free and, therefore, safe for people with gluten-intolerant diseases.

How to Substitute Cornstarch for Flour

A lot of recipes interchangeably use flour and cornstarch as a thickener, a coating or as another ingredient. However, while substituting one for the other, how much you use and how to use it differs from one cooking method to another; whether you are deep frying, baking or using the flour/ cornstarch to thicken sauces, gravy or pie fillings.

Substituting cornstarch for flour in sauces, gravy or pie fillings

Most people prefer cornstarch to flour as a thickener in sauces, gravy and pie fillings. The taste of the two is different, and flour appears cloudy, while cornstarch has a shiny appearance. 

All starches have thickening agents, and flour and cornstarch are no different. They act like a sponge by absorbing liquid and expanding, then gelatinize and firm up when cold. 

And since cornstarch is pure starch while flour is partly starch, it is a stronger thickener. You will need a double amount of flour to achieve the same thickening properties as cornstarch

Cornstarch vs flour

  • To use cornstarch as a thickener, you’ll need to first mix it with cold water to form a slurry. On the other hand, flour is first cooked with fat to form a roux. The slurry is added towards the end of a recipe, while a roux is added at the beginning.
  • You’ll need to cook the flour longer to remove the floury taste. Cornstarch should be cooked on a higher heat and for a shorter time to activate the thickening agents.
  • Flour makes the sauce opaque and cloudy, while cornstarch gives it a shiny and translucent finish. This makes cornstarch more desirable, especially for fruit pie filling in different sauces.
  • Cornstarch doesn’t thicken nicely with acidic foods. So, if your food has tomatoes, lemon juice, vinegar, egg yolks or butter, you might prefer using flour. Adding too much cornstarch to foods may turn them spongy and won’t freeze well.

Credit: Onga Ghana

Substituting Cornstarch for Flour in Fried Foods

Both flour and cornstarch can be used to coat fried chicken, fish and other foods before deep frying. Generally, cornstarch yields a crispier coating than flour and absorbs less fat. Contrastingly, more flour is needed to achieve the same effect, thus leading to a chewy texture.

Usually, recipes that call for the crispiest exterior require a 50/50 blend of both flour and cornstarch for a perfect balance and beautifully browned coating.

Important to Note: Make sure to apply a thin, light coating of the flour on the food you are deep frying. A heavier coating may make your food gummy.

Substituting Cornstarch for Flour in Baking

Baking is where you can never use flour and cornstarch interchangeably. For instance, a cake recipe will not work out if you use cornstarch instead of flour. This is because baked foods depend on the protein found in gluten to form their body and texture.

However, adding just a little cornstarch to a cookie or a cake recipe results in a more tender product. You can simply replace 2 tablespoons of flour with cornstarch.

Conclusion

While most people are aware that they can substitute cornstarch for flour, not many have an idea of how to go about it. Except in baking, all you need to do is to substitute cornstarch for flour in a ratio of 1:2. With this, you’ll never miss a recipe that calls for cornstarch while you have flour in your pantry.