If properly stored, cornmeal stays fresh on the shelf for approximately one year. If it is kept in an airtight, moisture-proof container, cornmeal can remain in the freezer for years.
On the shelf, cornmeal should be stored in a cool, dry location. The storage container should be airtight. Heat and dampness encourage mold growth, which makes cornmeal unusable. Higher temperatures provide a good breeding ground for insects.
Cornmeal can be stored safely in an airtight plastic food bag. The bag is then put into a large, lidded, clean airtight container. This is placed in a cool, dry and dark location off the floor. Air must be squeezed out of the plastic bag whenever it is opened and resealed.