corn starch/cornflour

Cornstarch (also known as cornflour in British and Commonwealth English) is a refined carbohydrate extracted from the endosperm of corn (maize) kernels, produced through a milling and processing technique that isolates the starchy portion from other kernel components. The ingredient is a white, fine powder with a neutral taste and is composed almost entirely of amylose and amylopectin starches. Cornstarch is produced by soaking dried corn kernels, grinding them to extract the starch granules, and then drying the resulting product into a fine powder with exceptional purity.

Chemically, cornstarch consists of approximately 25-30% amylose and 70-75% amylopectin, giving it distinctive thickening properties at different temperatures. The ingredient has a bland flavor, making it suitable for use across sweet and savory applications without imparting taste.

Cornstarch serves primarily as a thickening agent in sauces, gravies, soups, and custards, where its starch granules absorb liquid and swell under heat to create viscosity. It is also used extensively in baking and confectionery to lighten cake batters, reduce gluten development in pastries, and provide texture in cookies and cakes. In Asian cuisines, cornstarch is a crucial component of batters for deep frying (especially in Cantonese cooking), where it creates a crispy exterior, and is used to coat meats before stir-frying to seal in moisture. Cornstarch is also employed as a dusting agent to prevent sticking in dough handling and as a base in puddings and instant desserts.

When using cornstarch as a thickener, it must be dispersed in cold liquid before addition to hot preparations to prevent lump formation; this slurry is often called a "slurry" or "liaison." Cornstarch-thickened sauces may become thin again if overcooked or if acidic ingredients are excessive.