cornstarch mixed with tablespoon water

Cornstarch slurry is a mixture of cornstarch (finely ground endosperm of corn/maize kernels) suspended or dissolved in liquid, typically water, used as a thickening agent in cooking. Cornstarch itself is a refined carbohydrate extracted from corn kernels, consisting almost entirely of amylose and amylopectin starches. When combined with cold water, it forms a slurry that remains opaque and sediments over time; when heated above 60–70°C (140–160°F), the starch granules absorb water, swell, and gelatinize, creating a translucent, glossy thickening effect. This mixture is neutral in flavor and creates a clear gloss without cloudiness when properly cooked.

Cornstarch slurry is primarily used as a thickening agent in sauces, gravies, soups, and stir-fries across Asian, American, and European cuisines. It is particularly valued in Chinese cooking for achieving a silky, glossy sauce texture without the opacity that flour produces. The slurry is typically whisked into hot liquids while stirring constantly to prevent lumps and ensure even distribution. Common applications include sweet and sour sauces, pan sauces, dessert fillings, and glazes. Because cornstarch creates a clean, shiny finish and does not require cooking-out raw flour flavors, it is preferred for delicate applications where visual clarity matters.