Corn starch, cornstarch, cornflour or maize starch or maize is the starch derived from the corn (maize) grain or wheat. The starch is obtained from the endosperm of the kernel. Corn starch is a popular food ingredient used in thickening sauces or soups, and is used in making corn syrup and other sugars.
Cornstarch was discovered in 1840 by Thomas Kingsford, superintendent of a wheat starch factory in Jersey City, New Jersey. Until 1851, corn starch was used primarily for starching laundry and other industrial uses.
Cornstarch is used as a thickening agent in liquid-based foods (e.g., soup, sauces, gravies, custard), usually by mixing it with a lower-temperature liquid to form a paste or slurry. It is sometimes preferred over flour alone because it forms a translucent mixture, rather than an opaque one. As the starch is heated, the molecular chains unravel, allowing them to collide with other starch chains to form a mesh, thickening the liquid (Starch gelatinization).
It is usually included as an anti-caking agent in powdered sugar (10X or confectioner's sugar). Baby powder often includes cornstarch among its ingredients.
Cornstarch when mixed with a fluid can make a non-Newtonian fluid, e.g. adding water makes Oobleck and adding oil makes an Electrorheological fluid. The concept can be explained through the mixture termed "cornflour slime".