Adjusting hop additions for varying AAs

[Tidwellc]

I've been brewing for a while now, but something struck me that I never gave a whole lot of thought to before. A lot of recipe planners and recipes I use quote a specific AA unit for the hops (in addition to quantities). I've usually just thrown in the quantity called for and figured it was close enough. But for a recent brew, the hops the LHBS had were WAY lower in alpha acids than the was in the recipe. Like, from 5.5 down to 1.

Do any of you guys make adjustments for this? I usually use the brewer's friend recipe calculator before each brew. My thoughts are to note the IBU contributions of each hop addition, then input the actual AA's, and then adjust each addition back up to the previous IBU, and make sure the total IBU is pretty close to the original. Am I on the right track?

 

[RPh_Guy]

Do any of you guys make adjustments for this?

Yes, always. I adjust quantities of any hops boiled 30 minutes or longer.
I would generally not adjust the quantity of flavor/aroma hops added at 20 minutes or less.

Cheers

P.S. And I would check with the hop supplier (not the LHBS) to make sure that's not a typo.

 

[Tidwellc]

I would generally not adjust the quantity of flavor/aroma hops added at 20 minutes or less.

Is this because the oils and other compounds contributing to the aroma/flavor are not likely to change like the alpha acids?

 

[RPh_Guy]

Is this because the oils and other compounds contributing to the aroma/flavor are not likely to change like the alpha acids?

Exactly

 

[Tidwellc]

Exactly

Cool! Thanks makes sense. Eager now for my next batch with proper hop additions

 

[RM-MN]

I usually use a neutral flavor bittering hop to get the base bitterness adjusted for the AA of that hop, then add the rest without worrying about the additional bittering. Any hop added in the last 10 or less minutes should add little to the bittering, mostly flavor and aroma.