Cornstarch is a versatile pantry ingredient used as a thickener for soups and gravy, as a baking ingredient, for batter-frying, and various other uses. So, how is cornstarch made?
Cornstarch is separated from the starch-rich endosperm of corn kernels. Commercial wet milling softens the kernels and separates the germ, fiber, protein and starch. The starch is washed and dried into the familiar fine powder.
Let’s look at the process and how the starch is used.
Cornflour Vs. Cornstarch
Names vary by region. In the United States, corn flour usually means finely ground corn, while cornstarch is the separated starch. In the UK, ‘cornflour’ commonly means cornstarch.
Whole-grain corn flour uses the entire kernel; refined corn flours may have some components removed.
Whole corn flour is used in cooking and baking; its color depends on the corn variety.
Whole-grain corn flour retains more of the kernel’s protein and fiber than separated cornstarch.
Now, the production of cornstarch involves an elaborate and detailed process because it uses only the endosperm of corn.
The endosperm contains starch and protein. Producing cornstarch involves separating the starch from the other kernel components.
In wet milling, the kernels are softened and ground, and their germ, fiber, protein and starch are separated.
The separated starch contains much less fiber and protein than the whole kernel.
Cornstarch and whole corn flour therefore have different nutritional profiles and cooking functions.
If we compare their taste, cornflour tastes like corn.
However, cornstarch lacks the distinct earthy, sweet taste of corn.
It is a mostly flavorless source of carbohydrate, with much less protein and fiber than whole corn flour.
It’s mainly used to add texture to a dish and thicken it. It adds no flavor to a recipe.
Cornstarch is produced using a detailed and complex processing technique.
Let’s look at it in detail.
How Is Cornstarch Prepared?
Corn kernels contain starch, protein, oil and fiber.
This is the region beneath the outer husk.
The husk is a fibrous and tough material. It’s inedible and removed to consume the corn.
Once you get rid of the husk, you will be left with corn kernels that are embedded in a solid mass.
That solid structure is the cob. The germ is a small part inside each corn kernel.
The corn kernels contain the endosperm. It’s the starchy center of corn, which is used to make cornstarch.
Commercial wet milling separates kernel components through soaking, grinding, screening and other steps.
This is a time-consuming and elaborate process.
Now, not all corn is suitable for making cornstarch.
Corn that is more starchy than sweet is chosen for the purpose.
The procedure to extract cornstarch from it is as follows:
- The first step in the extraction process of cornstarch is removing corn kernels from the cob and soaking them. Soaking helps the grain soften and makes it easier to separate.
- Once the hull and germ have been separated, the endosperm is revealed. It has protein and starch in it. You only need the starchy bit to make cornstarch. So the next step is to separate the starch from the protein.
- A wet slurry is made by mixing the water and starch. The starch is washed several times until it’s pure. Finally, the remaining slurry is dried and milled into a fine powder. This is pure cornstarch. You can directly use it in your recipes.
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4 Uses Of Cornstarch
Cornstarch is a fine white powder.
It doesn’t have any discernible taste or smell.
Use cornstarch according to a recipe rather than tasting the raw powder.
To use it in recipes, cornstarch is often mixed with a suitable liquid to form a watery mixture.
Here are the most common uses of this powder.
1. Thicken liquids like soups and gravies.
Mix ordinary cornstarch into a little cold liquid until smooth, then stir the slurry into the hot dish as the recipe directs. The granules disperse in cold water; they do not dissolve and gelatinize simply from being stirred.
Heating with enough liquid makes the starch granules swell and thicken the mixture. Argo’s preparation guidance explains the cold-slurry method and gentle stirring during cooking.
2. Substitute for egg in baked goods.
Cornstarch can help bind or thicken some egg-free recipes, but it cannot reproduce every function of an egg. Eggs may provide structure, moisture, emulsification or lift.
Use a tested egg-free recipe rather than a universal spoonful-of-starch substitution, especially for cakes that depend on beaten eggs.
3. Add more structure to desserts.
Cornstarch can thicken cooked puddings, custards and fillings when heated with sufficient liquid. In some baked recipes it changes tenderness or structure.
The amount and method matter. Adding a cold slurry to any batter does not guarantee a light or chewy result, and too much starch can change the texture.
4. Batter and coating for deep-fried food items.
Cornstarch can be used as a batter for deep-frying vegetables, meat, and other fillings.
Some tested batter recipes combine cornstarch and water without egg. This forms a suspension, not a true solution, and is not a universal replacement for egg.
What Is Modified Cornstarch?
Modified cornstarch has been processed to change how the starch performs, such as its thickening behavior or stability in a particular food. The term does not by itself mean genetically modified corn.
Physical, chemical or enzymatic treatments can produce different functions. A product used in an instant sauce may behave differently from ordinary cornstarch, so follow the label rather than assuming it needs the same heating method.
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How Is Modified Cornstarch Made?
Manufacturers choose a starch and treatment for the intended food application. The FDA lists food starch-modified and its applicable regulation.
The purpose is not simply to prevent ordinary cornstarch from quickly spoiling. Dry cornstarch is a pantry ingredient: keep it tightly closed, dry and protected from contamination, and follow the manufacturer’s storage guidance.
Do not assume a modified-starch product is allergy-free. Check its stated source, ingredient list and any allergen or gluten-free labeling relevant to your needs.
