wort circulation effect on hop utilization

I recently incorporated a pump for whirlpool chilling into my system.  I was wondering about knockout hop utilization if the pump is running.  Does circulating the 210 - 200F wort through the pump create more bitterness than if it was just sitting static?  I didn’t know if part of hop utilization was the movement and heat created during the boil that might be similar when running wort through a pump and doing that for a 20-30 hop stand might be just like boiling.

Thoughts?

the short answer is yes. how how much more % you are extracting i’m not sure. depends on what hops and how long/vigorous your WP is. Just my common sense opinion on that no real science.

Stone has achieved up to 30% of the IBUs in a WP on the enjoy by beers.

You might be able to find more info on this in Mitch Steele IPA book.

I hope to have time this winter to do some studies about IBU contribution from whirpool hops.

I’d love to see that, Denny.  I don’t perceive many IBU at cooler temps but I’m sure they’re there. It’d be great to see some data on it !

Whirlpool above 160/180F? Or dropping the temps quickly below that? Gotta be a difference in isomerization… Now I need to reread Stan’s Hops book and Mitch’s IPA book. I might have this wrong.

I’d also love to see some data and testing on this subject from both a numbers and (more importantly) taste perception perspective.

M.S. Book page 208 "remember that isomerization of hop AA to iso-alpha acids will occur at temps above 185  F "

if you want to increase the IBU levels you must keep the WP at or above 185 F

But does wort movement add any utilization?  I understand that I am getting bitterness during the whirlpool.  It is more of a question of how much.

depends but it can be as much as 20-30% based on what his book says. Yes the movement is needed in order to achieve the extraction.