High vs. low alpha acid flavor and bitterness question

Greetings all!

I started thinking about this the other day during a (relatively) mindless drive home...

When we formulate our recipes for hop additions, we tend to focus on meeting an overall bittering level and adjust the amount of hops we used based on the alpha acid. When it comes to hop flavor, however, does the same thinking apply, i.e., if you have the same calculated bittering value for a flavor hop addition, will you have comparable "strengths" of hop flavor from a high vs. low acid hop?

An example:

You have two hops, one with an AA of 4% and the other 8%. Let's also assume that they have similar flavor characteristics. In terms of bittering levels, you would use half the amount of the 8% hop as the 4% to reach a given bittering level.

Would you then have the same flavor "strength"?

Is it only the AA that contribute to flavor, or are there other aspects that come into play that would potentially be stronger with the lower AA hop, since you'll be using twice as much weight-wise?

No. Alpha acid levels are directly proportional to bitterness levels, given equal characteristics of the boil. Alpha acid levels are NOT directly proportional to flavor or aroma levels.

+1, AAs are completely unrelated to flavor/aroma. IMO, you shouldn't be altering late adds based on AA levels, only bittering adds

+1, +1

I look at IBUs from every contribution so that I can watch total IBUs. But I look at the 30 and less minute additions as flavor somewhat proportional to weight.

ayoungrad said:

+1, +1

I look at IBUs from every contribution so that I can watch total IBUs. But I look at the 30 and less minute additions as flavor somewhat proportional to weight.

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Thanks!

This is kind of what I was driving at with my original question, that is, will the beer be "more hop flavorful" with 2 oz of a 4% hop vs. 1 oz of a 8% hop @ 10 min, seeing that the IBU contribution from each will be the same.

You're not going to realize any bitterness to speak of with the flavor and particularly aroma additions. The lupulin that contains the humulones and lupulones won't isomerize without at least about 40 minutes of boil.

Pilgarlic said:

You're not going to realize any bitterness to speak of with the flavor and particularly aroma additions. The lupulin that contains the humulones and lupulones won't isomerize without at least about 40 minutes of boil.

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I've never heard this before.

I have read quite a bit and I've heard some differing opinions about hop utilization but never that there is zero utilization less than 40 minutes. Even Garetz (which I have found to result in predicted IBU values below what I taste with my set-up) predicts utilization in as little as 10 minutes and Garetz seems to be the most in-line with your statement.

I love hops and bitterness. I rely mainly on Tinseth and I have never been disappointed with bitterness levels despite deriving 1/3-1/2 of my IBUs from the final 30 minutes of my boils.

Having said this, I'm always up for learning more. Do you have any info I could read or is 40 minutes more based on your personal experiences?

Thanks, Ayoungrad. I'm going to back way off my earlier statement, having checked utilization tables. Never mind.