questions about hop AA extraction

[flyinfinn]

Here's the deal. With the hop blocker from Blichman, it says to whirlpool the wort and let sit for 20 min to let everything settle out. This is fine if you are chilling at the same time. We just started using a plate chiller so we r chilling as we pour off into the carboys. My question is, is there going to be significant bitterness extraction during this 20 min lag between the end of the boil and chilling seeing that the wart will be above 200 degrees nearly the whole time? Are the late addition/aroma hops going to be affected? At what temp does bitterness extraction stop? Would it be better to add the aroma hops a couple minutes before we start the transfer from boil kettle to carboy? Thanks for the help. Matt

[Brewdouche]

...My question is, is there going to be significant bitterness extraction during this 20 min lag between the end of the boil and chilling seeing that the wart will be above 200 degrees nearly the whole time? Are the late addition/aroma hops going to be affected?

Yes, and Yes, Alpha extraction stops somewhere between 190-170

...Would it be better to add the aroma hops a couple minutes before we start the transfer from boil kettle to carboy? Thanks for the help. Matt

I think and do yes