Adjusting for age/storage of hop pellets?

[agentEhrman]

OK, so I plan to brew up an expensive batch of imperial stout tomorrow. I have the recipe all planned out, as well as all my ingredients.. well, almost all of my ingredients. I'm missing my bittering hops, which is 1oz nugget. I have some warrior and I am thinking that they would be a suitable replacement for nugget. The problem I have is, I have heard that the alpha % drops drastically from improper storage and age. I have had the warrior since early august. They came vacuum sealed and presumably well stored and fresh, although I know they were 2010 hops. After using them, I double zip locked them and stored them in my freezer. Since I don't have a vacuum sealer yet, and since these were already old when I purchased them, should I adjust the weight of them up a little bit for alpha loss?

Any advice or opinion is appreciated!

 

[chemicalcraig]

You should be fine. Warrior is a stable variety and has good storability. I still have some 2009 hops in the freezer that I've been using that still smell fresh as the day they were picked and work just fine. Smell them when you open them. If they smell rotten, or freezer burned, ditch them. Otherwise, you'll be alright.

 

[agentEhrman]

Sounds like solid advice, thanks chemicalcraig.

 

[theveganbrewer]

There is a function on BeerSmith and ProMash that calculates the deterioration of alpha acids, which helps you adjust for bitterness.

 

[JLem]

Here's a good article of hop storage and degradation. It includes a formula for adjusting the alpha acid % depending on type of hop, and method and length of storage.

http://morebeer.com/brewingtechniques/library/backissues/issue2.1/garetz.html