Storing brew hops is very important. Any amount of heat or warmth speeds up degradation of the hops. Oxygen causes oxidation that affects the consistency of the hops and the quality of their oils. Hops are normally stored within a few days after harvest and kept in cold temperatures at minimum. In most instances, farmers pelletize and pakage the hops in air-tight, vaccuum-sealed bags to preserve their freshness. Once sealed, the brew hops can be stored in a freezer for two to three years to make your craft brew. The timing of the harvest is also crucial for long term storage of hops, so the Hop Storage Index is used to optimize storage of brew hops.