What Is Cornstarch and How Do You Use It?
Everything you need to know about the pantry staple.
Here’s the comprehensive cornstarch guide you never knew you needed:
What Is Cornstarch?
Cornstarch, the starch derived from corn, is made from the white endosperms found in the center of a corn kernel. These endosperms are ground into a fine, white powder that is commonly used as a thickening agent.
What Is Starch?
Starch is the most common carbohydrate in the human diet. It’s found in high quantities in wheat, corn, potatoes, and rice.
Fad diets from the last few decades have given carbohydrates a bad name, but make no mistake: People need carbs to survive.
Consuming an appropriate amount of carbs gives you energy, and is integral to keeping your central nervous system running smoothly.
Thomas Kingsford invented cornstarch in 1842 when he discovered a way to isolate endosperms from corn kernels while working in a wheat starch factory in New Jersey. However, Kingsford didn’t have food in mind—for the first few years of its existence, cornstarch was used to starch laundry.
When it was eventually recognized as a useful ingredient in cooking, cornstarch brands were among the many companies of the Victorian era to advertise using collectible trading cards.
The cards, which usually featured a picture on one side and an ad or recipe on the other, were often pasted into scrapbooks dedicated to storing the ads. These cards are now sold as collectors’ items in thrift stores and online. Hundreds, ranging in price from $1 to $60, are currently listed on eBay
Cornstarch is most commonly used to thicken liquid-based foods like soups, stews, sauces, or custards. When used correctly and in appropriate amounts, cornstarch is translucent and tasteless.
Cornstarch also has plenty of uses outside the kitchen—read more on creative ways to use cornstarch around the house here.
How to Use Cornstarch to Thicken a Soup or Sauce
WATCH: How to Thicken Gravy
It’s easy to use cornstarch as a thickening agent, but it’s important to do it correctly.
If you add it directly into the mixture you want to thicken, you’re going to end up with a clumpy mess.
Instead, you need to make a slurry (a mixture of a thickening agent and liquid).
To make a slurry for a soup or sauce, whisk equal parts cornstarch and cold water, wine, stock, or broth. It’s important to make sure the liquid is cold before adding the starch to ensure that its granules can easily disperse.
You can then slowly pour the smooth slurry into your simmering sauce, soup, stew, or gravy.
Cornstarch vs. Corn Flour vs. Cornmeal
Cornstarch, corn flour, and cornmeal are all derived from—you guessed it—corn. But there are a few differences that make them non-interchangeable in recipes:
- Corn flour is a finely ground powder made from whole corn kernels, while cornstarch is a finely ground powder made from just the starchy part of the corn kernel. Cornmeal is a coarse substance made from dried corn kernels.
- Cornstarch is mostly flavorless and is used to perform a job (thicken a mixture) and not to add taste. Cornmeal and corn flour both have an earthy and sweet taste that is easily detectable in food.
- Corn flour can be used in addition to or as a substitute for wheat flour in baking. It imparts a distinct taste and golden color. Cornmeal can be used in the same way, but will cause a textural difference in your finished product. Since cornstarch doesn’t contain protein or fat, it can’t be used in the same way as corn flour or cornmeal in a recipe.
Flour thickens in roughly the same way as cornstarch, but doesn’t produce a glossy shine. Arrowroot powder does produce a glossy shine, but will need to be cooked longer than cornstarch.
Read more about cornstarch substitutions here: What Can I Substitute for Cornstarch?
How to Store Cornstarch
Cornstarch should be stored in a cool, dark place. Most cornstarch you can find at the store comes in resealable containers, so just make sure the lid is firmly in place when you’re finished using the product. If stored correctly, cornstarch can be used indefinitely.