How long will specialty grains keep?
When cracked grains are exposed to air, oxidation will occur. This will diminish the original aromatic and flavor character of the grains over time.
Cracked grains are best used within two weeks of cracking. Although they will degrade with time, cracked grains can still be used several months after cracking if stored in a dry, air-tight container. Similarly, if the grains are still solid and have not been cracked, they can be stored in this way for up to a year.