What is the corn wet milling process?
The corn wet milling process separates corn by physical and chemical methods to produce starch, high protein animal feed, and corn oil. The starch is often processed further to make corn syrup, corn sugar, ethanol, or other products. Wet milling should not be confused with the alkaline cooking process or the dry-grind ethanol process. Cleaned (fine materials removed) corn is steeped in a weak sulfurous acid solution for 24 to 48 hours at temperature close to 50°C (122°F). The kernels absorb moisture, and the sulfurous acid breaks chemical bonds in the protein matrix which encapsulates the starch granules. After steeping, the corn is loosely ground to rupture the pericarp (outer seed covering) and release the germ (ideally intact). The germ is removed by utilizing its difference in density from the rest of the components (i.e. it floats). The remainder of the material is ground more finely and separated by screening methods (to remove fiber) and differences in density (starch from prote
