What Is Corn Syrup?

When I started to work a night shift at a bakery after cooking school, I was humbled by the odd hours. And I was equally humbled by corn syrup. 

What I had previously written off as overly sweet goo was the secret behind a delectably smooth pecan pie filling, the perfect chew of an old-school sugar cookie, and even the magic of marshmallow fluff. The bottom line: Corn syrup is a noble baking staple that even the pros count on. Here’s everything to know about this divisive sweetener. 

What is corn syrup, exactly? 

Corn syrup is a sweet, viscous syrup made from refined cornstarch and used as a liquid sweetener or thickener in candy, pies, jams and jellies, and even beer. 

At the grocery store, you’ll find two types of corn syrup: light and dark. Light corn syrup is a clear, clarified syrup that often contains a small amount of vanilla flavoring. Dark corn syrup is a combination of corn syrup, molasses, and caramel coloring, which results in a darker color and a sweeter flavor than light corn syrup. 

You can substitute one for the other in most recipes, but remember that dark corn syrup will affect the color of your recipe and provide a more intense and sweeter flavor. Light corn syrup may add a subtle hint of vanilla.

How to use corn syrup

Corn syrup is a baker’s secret weapon. It prevents sugar from crystallizing (or lumps from forming). It’s a common ingredient in caramel sauce and recipes that use a hot sugar syrup, like marshmallows or meringue. 

Whether you’re a novice or a vet at making caramel, use corn syrup to produce its signature smooth look and feel (and for a little extra insurance against graininess). The same goes for frozen custard. A small amount of corn syrup in the base adds density, richness, and can prevent the sugar from crystalizing. 

Corn syrup is also often used as a thickener, and it’s the key to the gooey filling of a classic pecan pie or the chew of certain cookies like snickerdoodles or oatmeal cookies. Corn syrup adds a gorgeous sheen to confections like chocolate fudge. Of course, it also adds sweetness, which is more than welcome when baking cakes, pies, cookies, and everything else in between. 

What is high-fructose corn syrup?

The corn syrup that you buy at the grocery store is not high-fructose corn syrup. While both are made from cornstarch, high-fructose corn syrup is ultra-processed. Cornstarch is converted into sugar to make regular corn syrup, but additional enzymes are then added. These enzymes turn some of the basic glucose molecules into fructose and makes the product sweeter. 

High-fructose corn syrup is found in many processed foods, like cereal, soda, and candy, as well as on fast-food menus. However, it’s only used by major food and beverage manufacturers, so you won’t find it in the baking aisle. 

What can you substitute for corn syrup?

You can substitute for corn syrup, but only in recipes where it serves as a primary sweetener or is the key to improved texture. Swapping in other syrups, like golden syrup, maple syrup, or agave syrups, work well for baked goods like cookies, cakes, and sheet pan treats like brownies or blondies. However, these substitutes lack corn syrup’s ability to prevent crystallization, a crucial factor in recipes like homemade caramel or candy. If crystallization prevention is essential, it’s best to stick with corn syrup.