Why You Should Always Keep Cornstarch in Your Kitchen

Chances are you have a box or canister of cornstarch sitting in your pantry right now. It's the sort of ingredient that makes it way into recipes of all kinds, but what is cornstarch and what does it do? Even the most seasoned home cooks may not know the answer to those questions, despite the number of times they've relied on this pantry essential. Rather than asking what cornstarch can do, it might be more apt to wonder what it can't do—after all, its uses are numerous and wondrous.

What Is Cornstarch?

Primarily used as a thickening agent, cornstarch is a gluten-free starch derived from the endosperm of the corn kernel, which gives the plant its energy. Many starches are made from grains—rice, tapioca, arrowroot, potatoes, and wheat—but cornstarch is the most commonly used among them.

Why is cornstarch such a popular thickening agent? Though most home cooks likely have all-purpose flour on hand, cornstarch is twice as powerful as flour when used as a thickener. 

History

When it was invented in New Jersey in the mid-19th century by Thomas Kingsford, cornstarch was used chiefly as a laundry aid and in other commercial applications. Eventually, it made its way into the kitchen.

Cooking With Cornstarch

Cornstarch helps thicken the liquid ingredients in sauces, stews, stir-fries, custards, puddings, and pastry creams. It's also commonly used in fruit pies to help hot juices set and make the baked pie easier to slice once it has cooled. 

In order for its thickening properties to be activated, cornstarch has to be heated to the temperature of simmering liquid. In the case of baking a fruit pie, that means once you see the thickened fruit juices bubbling up from the steam vents in the top crust. 

Thickening Soups, Sauces, or Stir Fries

When used to thicken a soup or stir-fry, cornstarch should not be added to the hot liquid directly. it's best to make a slurry first, which will prevent the starch from clumping when it hits the hot liquid.

To make a cornstarch slurry: Simply combine the starch with cold or room temperature water (or another liquid, like broth or milk) and whisk until smooth before adding to the hot liquid.

Fried Chicken and Other Fried and Roasted Foods

If you like to fry chicken, you'll want to combine cornstarch with flour and seasonings to make the world's very best coating for it. The cooks in our test kitchen swear that cornstarch also holds the secret to their all-time favorite chicken wings, the crispiest, crunchiest onion rings, and the most irresistible roast potatoes.

Desserts

Beyond puddings and fruit pies, cornstarch is worth keeping close at hand for other desserts. It's sometimes used as a gluten-free replacement for flour as in our Gluten-Free Fudgy Pecan Brownies and the delightfully tender Australian cookies aptly known as melting moments.

Other Uses for Cornstarch

Laundry

Just as it was used nearly 200 years ago, cornstarch can help keep laundry looking its best. Use it to get oily stains out of clothing (after frying all that chicken, maybe?) or to starch your shirts when they are pressed. 

Substitutions for Cornstarch

Using cornstarch in place of flour as a thickener in any recipe is an easy swap: If a recipe calls for 2 tablespoons of flour, you need 1 tablespoon of cornstarch.

Other Swaps

The thickening properties of cornstarch are comparable to arrowroot and tapioca. Either can can be used interchangeably with cornstarch, without any adjustment to the amount. And cornstarch can be used in place of arrowroot or tapioca starch as a one-for-one swap.

Storing Cornstarch

Despite any date you might see on the package, cornstarch shouldn't go bad or lose its power. As long as you keep it in a cool, dry place, free from moisture, it should last indefinitely on your shelf—that is, if you don't use it up quickly.