hop aging and degradation

[edisonst]

Ive got a half pound of saphir hops that have been in the freezer for about 8 months. They are no longer in the nitrogen barrier bag, but are double bagged in zip lock bags. They still have nice aroma and I want to use them up. At what point in freezer storage should I need to start calculating the degradation of alpha acids( calculator in pro mash). Im thinking of doing a "winter saison" with all saphir hops so I want to make sure the bittering value is still correct. When I bought the hops they where at 3.7AA. What do you bulk buying hop folks do? Any thoughts?

[Bugeater]

I start using the promash conversion beginning at about 6 months or when I open the sealed bag. I use August as the start date, not the date I got them. This corresponds to when they were picked. Based on perceived bitterness this seems to give me the right AA figure.

Wayne

[Jidas]

The IBU's in the finished beer really doesn't change that much with aged or miss treated hops, but the ratio in the type of hop acids do change when hops oxidize. The iso-alpha acids drop and oxidized forms of alpha and beta acids (along with the cheesy compounds) increase. Some of the oxidized alpha and beta acids are soluble and bitter and will help balance the bitterness lost due to the reduction of the iso alpha acids. The way you perceive the bitterness is different and it wont be as sharp as the iso alpha acids. So I guess.. yes, do what bugeater said. I just wanted to through that out there.