Single-hop APA series - different AA% and discrepancies in hop additions

[phenry]

So I'm doing a series of single hop APAs to showcase the characteristics of each hop, and I was wondering how to adjust the hopping schedules between high AA hops and lower AA hops. I just brewed one with Cascade, and my hopping schedule was (for an OG of 1.050 and 5.5% AA):

1.5 oz - 60 min
1.0 oz - 15 min
1.0 oz - 0 min
1.0 oz - 1 week dry hop

For a total of 37.3 IBUs (Tinseth).

Next I want to do one with Chinook. I'm working with 13.1% AA with these, so I'm wondering how to adjust the 60 and 15 minute additions. I still want to hit around ~37 IBUs. Would I leave the 15 min @ 1 oz and just scale down the 60 minute addition to match IBUs, or what? I want them to be relatively equivalent in flavor and aroma so one batch doesn't stand way out from any of the others.

 

[Hammy71]

If it was me I would scale back both of them. If the 60 minute addition was...say 32 IBU for the 5.5% Cascade, I would make the 60 minute addition of the Chinook come out the same. Obviously it won't be the same amount but significantly less. Play around with Beersmith so you end up with the same final IBU.

 

[BrewMU]

HBUs. To be honest, I don't remember what it stands for, but it's basically 'bittering points': Ounces X Alpha Acid Percentage (as a whole number). For example, if hop A has AA% 10, hop B has AA% 15, you would replace one oz of B with 1.5 OZS of A.
1.0 X 15 = 15, 1.5 X 10 = 15. If hop C had an AA % of 1, you would use 15 OZs. Not reccomended.
IBUs are more complicated and have to do with the boil time and volume, so it's easier to use HBUs when comparing hops or making a recipe.
I don't think bittering strength or AA % is relevant to late (>20 minutes boil) additions, unless you're really laying them in heavy.

 

[tre9er]

Hbu is homebrew bittering units

 

[tre9er]

Bittering generally comes from earlier hop additions because the compound responsible is a resin and thus is harder to break down into soluble form. Flavor and aroma come from hop oil, which is much more soluble

 

[bovineblitz]

I would match the IBUs for the 60min addition and use the same amount of hops for the rest of them. If you want the IBUs to be exactly the same, reduce the IBUs of the 60min addition a bit more to compensate for the bitterness from the 15min addition.

 

[phenry]

So some further reading on various sources revealed that oils are really what dictate aroma/flavor, so I'll try to base my 15/0/Dry hop additions primarily based on the oil amount/100g, with IBUs in close consideration, and keep the 60 minute based completely on IBUs. I'll probably end up with some funky amounts, but at least I can say I'm trying to be scientific about things, right?

 

[Backporchbrewery]

i would match the ibus for the 60min addition and use the same amount of hops for the rest of them. If you want the ibus to be exactly the same, reduce the ibus of the 60min addition a bit more to compensate for the bitterness from the 15min addition.

+1