Swapping Dry Hops: Adjusting for Alpha Acids

[HerbMeowing]

When subbing one dry hop variety for another ... should the addition's weight be adjusted to compensate for different alpha acid (AA) content?

Recipe calls for dry hopping w/14g Chinook @10.7% AA
Will be subbing Northern Brewer @4.8% AA

Adjusting for AA ...
14g @ 10.7% = 31g @ 4.8%

I can see adjusting AA for bittering and flavor additions but not sure if the same holds true when dry hopping since there's no isomerization.

[Beer-lord]

Everything I've read over the years says you do get some bittering from dry hops but there's no way to correctly know how much. Considering how much dry hops are used in a New England IPA and the fact that those aren't hoppy at all, it's not worth worrying about. Depending on the hop itself, you're going to get more aroma than flavor for just a few ounces used.

[HerbMeowing]

More interested to understand the potential difference in aroma ... given different the AAs ... than bitterness.

Probably need to evaluate based on oil content ... such as farnesene and myrcene ... than AA.

[Beer-lord]

Check out some of Scott Janish's site, specifically his blog section and Beer Studies section here: http://scottjanish.com/blog/

[mashani]

Probably need to evaluate based on oil content ... such as farnesene and myrcene ... than AA.

Yes, it is more about everything else in there then the AA specifically. A hop with more "total oil content" then another with the same AAUs is going to contribute more flavor/aroma. A hop with low AA but a high "total oil content" is a lot of bang in that department. What kinds affect what things you get.

[HerbMeowing]

Northern Brewer's typical 'total oil' content is ~2x Chinook's.
Will try using about half as much Northern Brewer than Chinook.