Looking at same hop with different AA%: is the lower % less flavorful or aromatic?

[Horseflesh]

OK, stupid question maybe from an intermediate brewer... But does the AA% in a hop correlate to how much flavor and aroma it has? Or is bittering power separate from the other traits?

Here's a specific example. I am looking over an old recipe that used German Hallertau hops for a late aroma addition. The Hallertau that I have in the freezer how has half the AA of the hops I used before. So do I need to add more to get the same level of aroma?

 

[Gnomebrewer]

Not a stupid question at all. Bittering is separate from the other traits. Use the same amount for the aroma addition regardless of AA but adjust your bittering hop if needed to keep the bitterness the same. For example, if the Hallertau in your recipe above was providing 4IBUs, it will now only give 2IBUs. Increase your bittering hop addition to provide another 2IBUs.

 

[Horseflesh]

Thanks for the confirmation!

 

[Northern_Brewer]

It's not a stupid question but there's no simple answer - there's a bit of correlation but they're not tightly linked. Hops are agricultural products that are subject to vintage effects just like grapes, although those effects are more marked in Europe than in places like the Yakima Valley. So part of the art of brewing is having the experience and knowledge of your ingredients to know that say 2016 was a bad year so you need more hops for a given aroma, whereas you'd need less of the 2017s. But even commercial brewers struggle to do this consistently.

In fact this year has been a really interesting one because of the drought in much of Europe in the early part of summer. At least for EKG that's been terrible for yields but quite good for bitterness, albeit it's quite "hard" - but the weather broke in mid August at the crucial time for flavour development, so the flavour isn't quite as good as you might expect.

Be prepared to experiment - personally I would add a little bit more of the low-alpha hops, but I'd see how that compared and be prepared to go up/down depending on how it turns out, these things are not set in stone.

 

[Horseflesh]

That all makes sense, thanks.

 

[mcgearybrewing]

It’s also dependent on the age of the hops in your freezer, unless they’re cryovaced in something other than oxygen they’re going to start deteriorating.

There are tables available to show you how much AA you will lose at certain temperatures.

Like was said above I would experiment and take meticulous notes.