Corn starch is used as a thickening agent. It’s made by grinding the starch found in corn kernels to a fine, white powder, which is added to soups, custards, puddings, stews and sauces, giving them a glossy sheen and a thicker consistency.
Corn starch has about twice the thickening power of flour and is less expensive than arrowroot, a similar food used as a thickening agent.
If it”s not properly incorporated, corn starch can form unappetizing lumps when added to hot liquids. Prevent lumps by whisking the corn starch into a small amount of liquid, (also known as a slurry) then add the liquid to your food. Re-whisk the slurry if it’s not used immediately. The starch will settle at the bottom of your bowl if you let it sit. Corn starch works immediately when it’s added to hot liquids, so it’s important to stir food constantly once it’s added.