Hop AA loss over time?

How much do my hops lose their potency over time? I have lots that are probably at least a year old, in a freezer, in vacuum sealed bags. Getting ready to make some hop forward IPA’s and want to adjust properly

I’ve never really read a way to calculate AA loss over time but maybe that’s just something I missed. If it were me I would buy a known ounce for bitterning and then back load at the end of the boil and dry hop with the older ones.

The book Designing Great Beers by Ray Daniels provides some qualitative data about how quickly different hops lose their alpha acid over time. Beyond that, I wish I knew how to determine this more quantitatively but I don’t. As a general rule, personally I figure hops lose about half their alpha acid after a couple years in storage. However this is totally just a swag, and I’m wrong about as often as I’m right. When using old hops, I use this estimate and then split the hops 50/50 with new ones where I know the alpha acid so that I know I’ll at least be in the general ballpark. But it is certainly a swag. The DGB book seems to be the only real scientific info out there to help us out, and even it is not very precise and is a bit dated. But it seems to me it’s all we’ve got.

Promash includes a calculator for that IIRC.

If you use them in a year or less I assume they will not loose any?

BeerSmith also includes a calc.

Great discussion – thanks for posting!

Unfortunately alpha acids and ‘actual’ IBU takes complex machines to be accurate. calculated IBU is a very loose estimate. I was given the opportunity to analyze actual IBU’s in my finished beer. I learned that calculated IBU, and actual IBU can be very very different. Without knowing your precise utilization, and true AA, it’s hard to be exact.

Because of this, i haven’t payed too much attention to AA outside of what my brewing programs advise. after that, it takes time to get used to your system, and your taste.

that being said. +1 to the calculators. all you can hope for, is the best estimate possible. Just keep in mind - that it’s an estimate.

(sorry if im preaching to the choir here. :lol: )

[quote=“S.Scoggin”]Unfortunately alpha acids and ‘actual’ IBU takes complex machines to be accurate. calculated IBU is a very loose estimate. I was given the opportunity to analyze actual IBU’s in my finished beer. I learned that calculated IBU, and actual IBU can be very very different. Without knowing your precise utilization, and true AA, it’s hard to be exact.

Because of this, i haven’t payed too much attention to AA outside of what my brewing programs advise. after that, it takes time to get used to your system, and your taste.

that being said. +1 to the calculators. all you can hope for, is the best estimate possible. Just keep in mind - that it’s an estimate.

(sorry if im preaching to the choir here. :lol: )[/quote]

Agreed. Calculated IBU’s are really just a tool to calibrate recipes to your system and palate. They are most helpful when making adjustments from batch to batch, trying to maintain consistency when repeating batches, or to get you into a ballpark when designing a recipe. You’re not going to be able to nail a specific measured IBU, but if you know what a 35 IBU beer tastes like when calculated with Tinseth on your system (for example), then you are going in the right direction.

I guess the reason for the original question is I am coming up on my 2 year anniversary of my first brew which was on Super Bowl Sunday 2 years ago. Extract, clueless, etc.

I have brewed some really good beers since then, some extract and some all grain and I have a ton of hops that I have been buying in the last 18 months. I am planning to brew 2 of my favorites in celebration of the 2 year anniversary. Probably a Chinook IPA and a Surly Bender. I know my Chinook Hops are at least 14-18 months old. So how much would I bump the original quantities so that I do not a lifeless IPA.

[quote=“560sdl”]I guess the reason for the original question is I am coming up on my 2 year anniversary of my first brew which was on Super Bowl Sunday 2 years ago. Extract, clueless, etc.

I have brewed some really good beers since then, some extract and some all grain and I have a ton of hops that I have been buying in the last 18 months. I am planning to brew 2 of my favorites in celebration of the 2 year anniversary. Probably a Chinook IPA and a Surly Bender. I know my Chinook Hops are at least 14-18 months old. So how much would I bump the original quantities so that I do not a lifeless IPA.[/quote]

If you had your hops vacuum-packed and in the freezer, then my WAG is the AA% is probably 80-90% of what you started with. You may not even notice a difference, but if you wanted to bump your additions by 10-20% that would be where I’d ballpark it.

That is what I was thinking, thanks