Cornstarch

Cornstarch, or cornflour, is the starch of the corn (maize) grain. It is also grown from the endosperm, or white heart, of the corn kernel. It has a distinctive appearance and feel when mixed raw with water or milk, giving easily to gentle pressure but resisting sudden pressure.

It is usually included as an anti-caking agent in powdered sugar (10X or confectioner's sugar). For this reason, recipes calling for powdered sugar often call for at least light cooking to remove the raw cornstarch taste.

Cornstarch or cornflour is also used as a thickening agent in soups and liquids. As the starch is heated by the liquid, the molecule chains unravel, allowing them to collide with other starch chains to form a mesh - thus slowing the movement of water molecules. This results in thickening of the liquid, be it soup, stock or other culinary liquids.

Manufacture

The corn is steeped for 30 to 48 hours, which ferments it a little. The germ is separated from the endosperm and those two components are ground separately (still soaked). Next the starch is removed from each by washing. It is separated from the gluten and other substances, mostly in hydrocyclones and centrifuges, and dried. (The residue from every stage is used in animal feed and other products.) Finally the starch may be modified for specific purposes.

Other

Amylophagia is a condition involving the compulsive consumption of excessive amounts of purified starch, often cornstarch.

Other names and varieties

• Called cornflour in Commonwealth countries.