Select mature corn kernels
Clean and remove debris, husks, and damaged kernels
Soak the kernels in water
Add sulfur dioxide or another steeping aid during soaking
Steep the kernels for 24 to 48 hours
Drain the steeping water
Grind the softened kernels
Separate the germ from the slurry
Remove the germ for oil recovery if desired
Fine grind the remaining slurry
Separate fiber from the starch slurry
Wash and screen the starch repeatedly
Remove gluten and protein from the starch suspension
Concentrate the starch by settling or centrifugation
Dewater the starch cake
Dry the starch to the desired moisture level
Mill the dried starch into a fine powder
Sieve the powder to ensure uniform particle size
Package the corn starch in moisture-proof containers