Pellets store better because, taking up much less room, they can be vacuum or nitrogen packed and stored frozen.

The Oregon station has been conducting storage characteristic trials since 1974. The following table shows the ranking of some popular varieties by % of alpha and beta acids remaining after 6 months ambient storage (in bale form.)

Cluster 85%
Galena 76
Perle 78
Nugget 74
Fuggle 74
Styrian 73
Willamette 68
Chinook 63
Hersbrucker 61
Liberty 56
Tettnanger 57
Saazer 55
Hallertauer 54
Spalter 55
Bullion 50
Hallertau Tradition 49
Santiam 45
Cascade 42
Crystal 41
Brewers Gold 34
Mt. Hood 38
Centennial 33
The figure shown is for the average of all samples tested since the program began, however, storage characteristics can vary widely from year to year.

Figures have not yet been published for the super-alpha varieties, but they are generally low, and are usually converted to extract as soon as practical after harvest.

These figures are for baled hops stored at ambient temperature. Of course, once pelletized, vacuum or nitrogen packed, and stored at cold temperatures or frozen, the drop off is much, much, smaller, but the ranking by variety does appear to be consistent.

Hops continue to be a major export item for the United States. Since 1995 we have exported more hops to Germany than we imported.

HOP UTILIZATION IN BREWING

While it is not the purpose of this work to go deeply into the chemistry of hops in the brewing process, it must be noted that the Alpha Acids in hops, because they are contained in hard resins, do not impart any bitterness. Alpha acids make up from 4 to 17% of the weight of hops. During the kettle boil the Alpha Acids are converted to beer soluble Iso-alpha Acids, mainly Isohumulone, which impart the refreshing, clean bitterness to beer.

Of course, during the lengthy kettle boil and conversion process most of the aromatic oils will evaporate. Therefor brewers wanting a beer with a distinctive hop aroma will add their aroma hops at the end of the kettle boil, or even later in the brewing process.

Beta Acids, about 5% of the hop weight, consist of Lupulone, Colupulone and Adlupolone. Beta acids of fresh hops are converted only slightly into soluble components, but in aged or deteriorated hops and hop products the Beta acids do tend to become oxidized into beer soluble constituents which can impact beer flavor.

Hops provide a vital element for the brewer to impart just the right character to his beer or ale. Brew on!