Cornstarch can be used as a thickener in many recipes. Because cornstarch tends to form lumps when mixed with warm or hot water, it is best dissolved in cold water. It is also found in many gluten-free recipes.
Cornstarch also has many uses in the manufacturing of environmentally friendly products. For example, in 2004, the Japanese company Pioneer announced a biodegradable Blu-Ray disc made out of cornstarch. The use for the plastic is vast, as it is a renewable plastic that has the benefits of being biodegradable, used in injection molding, in extruders, and other common milling processes.
A mixture of 1 part water to 1.5–2 parts cornstarch is a popular classroom demonstration of a dilatant (shear-thickening) fluid, often called Oobleck. When struck, cut with a knife, or worked vigorously in the hands, it behaves like a pliable solid, but if allowed to sit for a few seconds, it flows as a viscous liquid. It can also be used for making highly flammable and explosive jellies.
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.
Amylophagia is a condition involving the compulsive consumption of excessive amounts of purified starch, often cornstarch.