• Welcome to the new forum! We upgraded our forum software with a host of new boards, capabilities and features. It is also more secure.
    Jump in and join the conversation! You can learn more about the upgrade and new features here.

Low Temp Whirlpooling


May 15, 2016
Reaction score
I have gone to whirlpooling my hops at lower temps than what gives bitterness.  I started whirlpooling at 170*F but have started reducing to 140*F or even 125*F.

I use my in-kettle wort chiller to drop the temp quickly to that desired, then pitch the hops and stir/whirlpool for about 20 min.

Is there any way to tell BeerSmith that my whirlpool is not going to raise the IBU on the beer?  Seems we need an input for the whirlpool temp and a time input.

Am I missing something?  Is it there and I just can't find it?  I have gone to just add a 0-minute hop addition.  Makes it harder for others or myself at a later date to follow the recipe.

Under 'options' > 'Bitterness' >> you can set the steep/whirlpool utilization factor to zero.  The steep/whirlpool utilization factor will zero out any IBU contributions from whirlpooling.
I understand how to change the "Steep/Whirlpool Util Factor", but many of us do a whirlpool hop addition at flame-out (200* down to 170*) and then an additional extended whirlpool hop stand at sub 170*.  Changing the utility factor as you suggest would result in initial flame-out additions adding zero bitterness.

In my electric set up, I have it programmed to cool to 170* at FO.  This takes approximately 10-12 minutes.  Once at 170* my program holds at 168* for an additional 20-30 minute hop stand.

Since many of us view these as two separate processes it would be nice to have an additional "aroma whirlpool" option when designing our recipes.  This way it's easier to capture total hops needed and at what time.

I don't think we need to get as intricate as time and temp as no system can really calculate bitterness that precisely in a generic way for all environments.  For me it's simply the convenience of not having to add aroma whirlpool additions in the notes section and remembering to add the amounts to my hops bill.
Greetings BrewKaiser - I'm reading a book published by BYO titled: Big Book of Brewing.  The following is a quote from the book:

  ....."Alpha acids will continue to isomerize after flameout until the temperature of the wort reaches about 175?F (79?C). Homebrewers trying to calculate a beer?s IBUs will need to guesstimate how much isomerization is occurring. The closer the wort is to 212?F (100?C), the higher the alpha acid isomerization rate."

I'm taking this quote to mean that the term "Whirlpool" hop addition doesn't actually start until the wort is below 175 degrees which is the temperature at which the isomerization of the hops stops (no rhyme intended).

So, a suggestion would be to actually enter your "whirlpool" addition twice.  Once as a kettle addition for as long as it takes your system to cool the wort down to below 175 degrees (10 to 12 minutes) and again in the whirlpool addition. Doing so should add whatever isomerization there might be for as long as it takes your system to cool.  Will this practice be 100% accurate?  I doubt it.  But it should be very close.

Just a thought.
Thanks KellerBrauer.

I totally agree that calculating isomerization factors below 212* is a guessing game.  I believe most brewers would agree with the quote you provided.  There are also some brewers experimenting with with "zero IBU" beers where all hops are added post boil with majority being sub 170*.  From 212* to 175* alpha acids will isomerize, but even below these temps these "zero IBU" brewers suggest that significant whirlpool contributions still provide perceived bitterness.

Anyway, as stated previously, I'm not concerned about calculating IBUs perfectly so much as being able to separate the two post boil processes to keep my brew session organized.  From 212 to 175 some isomerization will occur and it would be nice to capture that, at whatever ever hop utility % used.

I'll play with it a bit as you suggest.  I'm thinking I'll set utility factor to 5%.  I typically do equal parts of the same hops at FO and at WP.  From FO to 170* takes only 10 minutes so there's not a significant contribution here.

As more and more of us brew NE IPA style beers where there is an emphasis on post boil additions, I think BeerSmith will see more requests to either adjust Hop Utility Factor for each hop addition or to add an additional Whirlpool option.
Greetings BrewKaiser - it sounds like you have a pretty good handle on the situation.  5% Utilization factor for whirlpool sounds like it will work fine.  Once below 170 degrees, you'll start collecting all that wonderful hop flavor.

Bottom line is none of the greatest brews we all enjoy were perfect on the first run.  Use your intuition, brew your beer and see how it turns out.  If there's something you want changed, change it on the next run.  Who knows, maybe in a few years we'll see your brew highlighted in BYO!  ;)

Good luck!