cornstarch dissolved in 2 tablespoons water

Cornstarch, also known as corn flour or maize starch, is a fine, odorless white powder extracted from the endosperm of corn (maize) kernels through a wet-milling process. The starch granules are separated from the protein, fiber, and germ components and then dried and ground to an impalpable powder. When dissolved or suspended in liquid, cornstarch creates a slurry that serves as a thickening agent, with the starch granules swelling and gelatinizing upon heating to create viscosity and body.

Cornstarch is nearly pure carbohydrate with minimal flavor of its own, making it a neutral thickening agent suitable for both savory and sweet applications. It differs from whole corn flour (which retains bran and germ) in its refined, uniform texture and superior thickening power.

Cornstarch slurry—cornstarch combined with a small amount of cold liquid to prevent lumping—is a fundamental thickening agent in Asian, Latin American, and American cuisines. It is commonly used to thicken sauces, gravies, stir-fry sauces, puddings, and pie fillings. The slurry is added near the end of cooking and brought to a boil to activate the thickening properties; the result is a translucent, glossy sauce with a silky mouthfeel. Cornstarch is preferred over flour-based roux in Asian cooking for lighter, clearer sauces and in recipes where a gluten-free thickener is desired. It is also used as a dusting agent to prevent sticking and in batters for fried foods.