Are Cornstarch and Corn Sugar the Same? Unpacking the Sweet vs. Starchy Difference

December 11, 2025 •

2 min read

According to the Corn Refiners Association, the US corn refining industry is a major producer of both cornstarch and corn-based sweeteners. Despite originating from the same plant, these two products are fundamentally different in their structure, function, and processing. Are cornstarch and corn sugar the same? No, one is a complex carbohydrate used for thickening, while the other is a simple sugar used for sweetening.

Quick Summary

Despite both being derived from corn, cornstarch and corn sugar are chemically distinct products with different uses. Cornstarch is a complex carbohydrate for thickening, while corn sugar is a simple sugar (dextrose) for sweetening. This article details their differences, production, and proper application.

Key Points

Not the Same: Cornstarch is a complex carbohydrate for thickening, while corn sugar is a simple sugar (dextrose) for sweetening.
Different Function: In recipes, cornstarch provides texture and viscosity, while corn sugar adds sweetness.
Derived from Corn: Both products originate from the endosperm of the corn kernel but are processed differently.
Production Process: Corn sugar is made by converting cornstarch through hydrolysis, breaking down complex starch chains into simple glucose.
Sweet vs. Starchy: The core difference is between a tasteless, starchy thickener and a sweet, crystalline sugar.
No Interchangeability: Substituting one for the other in a recipe will fail due to their entirely different chemical properties and functions.
Avoid Confusion: Corn sugar is not the same as the liquid corn syrup; one is a powder, the other is a viscous liquid.

Understanding the Raw Materials: From Corn Kernel to Kitchen Staple

Both cornstarch and corn sugar are derived from the endosperm of the corn kernel, but their processing leads to fundamentally different products. Cornstarch is the refined starch itself, a complex carbohydrate made of amylose and amylopectin, which provides thickening capabilities. Corn sugar, specifically dextrose, is a simple sugar produced when cornstarch undergoes hydrolysis, breaking down the complex starch into individual glucose units, resulting in a sweet product.

The Production Process: From Starch to Sugar

The production process highlights the distinction between the two. Both begin with wet milling corn to separate its components.

Cornstarch Production

Cornstarch production involves steeping cleaned kernels, milling to separate components, and then refining and drying the pure starch slurry.

Corn Sugar (Dextrose) Production

Corn sugar production takes the pure cornstarch and subjects it to saccharification using acids or enzymes to convert the starch into glucose. This is followed by filtering, refining, and drying to create the crystalline dextrose powder.

A Tale of Two Carbohydrates: Functional Differences in the Kitchen

Their differing chemical structures result in distinct culinary uses. Confusing them can significantly alter a recipe's outcome.

Cornstarch's Role

Cornstarch primarily acts as a thickener in liquids when heated. It can also be used as a coating for crispy fried foods or as a binder in baking.

Corn Sugar's Role

Corn sugar (dextrose) is primarily a sweetener. It's used in commercial food production and can aid fermentation in brewing or contribute to browning and texture in baked goods.

Comparison Table: Cornstarch vs. Corn Sugar


Feature	Cornstarch	Corn Sugar (Dextrose)
Chemical Composition	Complex carbohydrate (polysaccharide)	Simple sugar (monosaccharide)
Taste	Tasteless	Sweet
Appearance	Fine, white powder	Fine, crystalline powder
Primary Use	Thickener, coating agent, binder	Sweetener, fermentation agent
Function in Recipe	Provides viscosity and texture	Adds sweetness and aids fermentation
Production Process	Wet milling and refinement	Wet milling, followed by hydrolysis

A Brief Word on Corn Syrup

Corn sugar (dextrose) is not the same as corn syrup or high-fructose corn syrup. Corn syrup is a liquid sweetener, while corn sugar is the granulated dextrose. HFCS undergoes further processing to convert some glucose to fructose.

Conclusion

While originating from corn, cornstarch and corn sugar are distinct products. Cornstarch is a complex carbohydrate for thickening, and corn sugar (dextrose) is a simple sugar for sweetening. Understanding these differences is key to successful cooking and baking, preventing culinary mishaps.

What to remember

Origin: Both come from the corn kernel but are processed differently.
Composition: Cornstarch is a complex carbohydrate, while corn sugar is a simple sugar (dextrose).
Function: Cornstarch thickens, while corn sugar sweetens.
Production: Corn sugar is made by further processing cornstarch through hydrolysis.
Culinary Impact: Using one in place of the other will lead to very different and likely undesirable results in a recipe.
Don't Confuse with Corn Syrup: Corn sugar (dextrose) is a granulated sugar, unlike the liquid corn syrup.
Key Distinction: Think of it as complex carbs (starch) versus simple carbs (sugar).

Frequently Asked Questions

No, you cannot use cornstarch as a substitute for corn sugar. Cornstarch is a thickening agent with no sweetness, whereas corn sugar (dextrose) is a sweetener. Using cornstarch instead of corn sugar will not provide the desired sweet flavor and will likely over-thicken your recipe.

Corn sugar is commonly known as dextrose, a simple sugar (monosaccharide) derived from cornstarch through a hydrolysis process.

From a nutritional standpoint, corn sugar (dextrose) and regular table sugar (sucrose) are both caloric sweeteners that should be consumed in moderation. Both can rapidly increase blood sugar levels, especially for individuals with diabetes. However, in fermentation, dextrose provides a clean flavor without cloying sweetness.

While both come from cornstarch, corn sugar (dextrose) is a dry, crystalline powder, whereas corn syrup is a viscous, liquid sweetener. The main difference is the form of the final product and the level of processing it undergoes.

If you use corn sugar instead of cornstarch in a sauce, it will not thicken. Instead of a thick, smooth sauce, you will end up with a very sweet, thin liquid.

The primary function of cornstarch is to act as a thickening agent. When heated in a liquid, its starch granules swell and burst, creating a viscous, gel-like consistency perfect for sauces, gravies, and desserts.

The main chemical difference is that cornstarch is a complex carbohydrate, or polysaccharide, made of long chains of glucose, while corn sugar (dextrose) is a simple sugar, or monosaccharide, consisting of single glucose units.