cornstarch

Cornstarch, also known as maize starch, is a carbohydrate extracted from the endosperm of corn kernels. It consists mainly of starch granules with small amounts of protein, moisture, and minerals. It is naturally gluten-free, though cross-contamination can occur in some processing facilities.

Production involves milling dried corn and separating the starch from bran and germ, followed by washing and drying to yield a fine, white powder. In addition to native cornstarch, commercially available products include modified starches—starch treated chemically or physically to improve stability under heat, shear, or acid conditions.

Chemically, cornstarch is composed primarily of amylose and amylopectin, with the ratio affecting gel strength and viscosity. When heated with water, the starch granules swell and gelatinize, forming a viscous paste; upon cooling, it often sets into a translucent gel. Granule sizes typically range from a few to tens of micrometers.

Common culinary uses include thickening sauces, gravies, soups, pie fillings, and custards, as well as improving texture in baking. Industrial applications cover paper, textiles, cosmetics, and pharmaceuticals, where cornstarch or its modified forms act as stabilizers, binders, or thickeners. Modified starches broaden performance by withstanding higher heat, shear, or acidic conditions.

Storage should be in a cool, dry place to prevent clumping and degradation. Cornstarch is gluten-free by default, but products processed in facilities handling gluten may be at risk of cross-contamination, so labeled gluten-free options are advisable for sensitive individuals.