Whirlpool Hops Substitution Amount

I have a brown ale recipe that I’m looking to brew this weekend.  There is a 30 minute hop addition and a 25 minute whirlpool addition.  It originally uses Columbus for both.  I do not have so I’m going to substitute Chinook.

For the 30 minute addition I plan on adjusting to the amount to maintain similar AAU.

My question is about the whirlpool substitution.  Should I aim to maintain AAU or amount or somewhere in the middle?

Thanks ,

Tommy

I guess my question would be what temp whirlpool?

I mean if we’re talking flame out, add hops, and whirlpool at 190-200*F, then I imagine you’re looking for the bitterness (because you’ll drive off the oils) so I’d account for the bittering.

But if you cool the wort to say 160*F or so, then adding hops and whirlpooling, I think bittering is not the point — it’s the oils you’re attempting to preserve. Even though I imagine some hops have more oils than others, at that point I’d match weight for weight.

Add at flameout and whirlpool for 25 minutes.

I generally see temp drop to about 185 over that time.

Sounds like I should be looking to maintain AAU.