Crushed Crushed grains should be used within 2 months of crushing. Uncrushed Uncrushed grains can keep up to 1 year. Old grain can go stale on you which will affect enzyme activity so it is always recommended to use it as quickly as possible. Grain should be always stored in a cool, low moisture environment. If possible, try to remove as much air as possible from your storage container. If you must store for an extended period of time you should think about investing in a vacuum sealer. As a rule of thumb always taste your grain before use. If it still tastes fresh and bread-like you are good to go. Freezing is not necessary.