Storage of hops 1920 - 1939

One of my questions has been answered today. What does "CS" mean in hop entries in brewing logs. It turns out my guess was right: Cold Store.

How much hops deteriorate over time is a topic that's intrigued me for quite a while. Ever since I first noticed hops more than a year old in brewing logs. It seems that, if stored correctly, hop deterioration isn't that dramatic over the first 18 months.




Storage of hops
Hops deteriorate over time, losing both bittering and preservative qualities. This meant it was essential to store them carefully. By keeping the hops at 32º Fahrenheit in a dry atmosphere, their deterioration could be slowed significantly. Most of a season's crop was in cold storage by December or January.

The table below shows the difference between hops kept in a cold store and those in an ordinary warehouse.


In practice, old hops had better preservative qualities than the anaylses would suggest.





Another way of preserving hops was to compress the hop pockets by means of an hydraulic press to a half or one third of their original size. The compressed pocket was then bound with iron straps. Compression alone worked as well as cold storage up to about 18 months. A combination of compression and cold storage produced the best results.