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Two months ago I brewed an ale with three hops - cascade, northern brewer and saaz. I immediately put them in the freezer, but want to know how to best use them (if there has been any degredation).

So, preferably (to make this a complete guide) I'd like answers to the following questions:

How does freezing effect

  • Aroma potential
  • Bittering potential
  • Flavor potential

in the following forms of hops:

  • Whole
  • Plug
  • Pellet

My hops were whole, and frozen 30 minutes after opening the vacuum bag (in the same bag, but no longer with vacuum). I've read that I should add 30% extra bittering hops. Does flavor/aroma potential degrade more/less?

There is a similar question on this site, but it asks what the best way to store opened hops is, but not if the effect of storage is.

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30% after how long of storage. The loss in potential is a slowly but constantly moving target. – brewchez Sep 15 '11 at 19:31
@brew Two months of storage. Maybe 30% is alot, I'm just looking for general best practices. I mean, most if not all brewers must surely face this problem sometime... It standard practice to simply use them as ordinary? – Max Sep 15 '11 at 20:16
Choosing Cascade hops at random, Promash shows that 6 months of storage at -10F (average freezer temp) reduces the AA from 5.75% to 5.35%. Not much..... – Denny Conn Sep 15 '11 at 21:49
And Promash is up to date... – brewchez Sep 16 '11 at 11:40

The freezer greatly slows degradation of the hops. I've never experienced any negative effects from storing hops in the freezer. It's the preferred method of storage. The absolute best thing you can do is vacuum seal them before storing them in the freezer. Barring that, using a resealable bag that you remove as much air as possible from will work well.

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You questions are good ones, unfortunately the effect of storage is somewhat variety dependent. Some hops store better than others, so there is no definative answer there. I will say that the effect is not broken into aroma, flavor or bittering either, seeing how its all based on the storage effect on the gland of the hop. Aroma, flavor and bittering all come from the same place, its the boil time that really determine what you are getting from the hops.

In general, there may be some statistics out there that give the degradation rate of each variety under certain storage conditions. I haven't seen a clear chart or table with that data though.

I have stored hops in the opened mylar bag I got them in wrapped in a sealed ziploc in the freezer for a couple years and not really noticed a huge change in bittering potential.

30% figure seems high, but its time dependent too. The hops slowly loose their alpha potential with time. A month later you probably don't notice the change, a year later...maybe.

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I think there is some great advice here but I listen to a lot of bodcasts and there is a particular Beersmith podcast called "hop chemistry" where James Altwies from Gorst Valley Hops gives some great info and mentions that they freeze their hops at an insanely low temp.

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I heard that postcase, and I understood that the insanely low temp was mainly to preserve the aromatics, since they can become volatile at fairly low temperatures. – mdma Jul 11 '12 at 15:21

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