alpha acid loss in storage
Anyone know how accurate the AA loss values for hop storage are? According to some figures the 2007 crop hops I still have are practically useless from a AA standpoint. Can these hops be used as aroma hops still? Any ideas here as I imagine a few of us may have overbought during the "crisis".
I'm still using some hops from 2005 harvest. While not the freshest, they do the job. The alpha acid % stays constant for a period in storage. The quality of the bitterness however changes as some contributing compounds are broken down while others build up leading to a more harsh bitterness. This assumes the hops are stored properly.
Big things are proper storage, proper packaging and the “storage-ability rating “ of the variety in question. Remember pellets should store better than cone.
Assuming you have been storing your hops properly and that the integrity of the packaging material has not been compromised you can plan to use 2007 hops this year and next year and…….
I see some good answers here, but will make a few comments. Years ago I did some tests on pellet storage in our warehouses. I found that many hops even after 5 or 6 years had little negative affect. Now these were kept in good vacuum polyfoils and the warehouse is kept around 28 degrees F. Whole hops will deteriorate even in cold and after a few years will have lost a considerable amount of alpha acid. Part of the answer to the question relates to variety. Some are very stable like Magnum, Perle, Nugget and Cluster. Others are not very stable like Columbus, Tomahawk, Zeus, Bullion and Brewers Gold. Others will follow a middle ground, but variety is the first thing I consider when thinking about deterioration. For whole hops, we have been doing a nitrogen flush and vacuum seal for customers and this has helped immensely with cutting down the deterioration. Bottom line is you have to think about the variety, how cold it was and is being stored and if it has a good oxygen barrier around it. If you really want to know how much it has deteriorated, one could always use a lab and have them analyzed. My wife does this for Hopunion and for other breweries and growers. The cost is $35 and what you get is the alpha, beta and HSI which is a measure of oxidation for the sample. Trust this helps
Ralph is on a roll! Thanks for the posts. Keep the great the insight coming!