[evil_morty]

I've started calculating my hopstand IBU @ 5 minutes.  I feel it is pretty close.  Not that it makes much difference really.  I saved my last IPA and compared it my latest that just carbed.  My FW hops went to 60min.  I reduced the honey malt slightly.  I tried to keep everything else the same.  My latest has more pronounced bitterness.  I do think FW gives the more rounded experience.  In my IPA I kind of liked the 60 min better.   

I've used FW a handful of times.  I've never done anything to try to determine if I like it better.  I know some people really like it - particularly for german styles that are less hop heavy.

[dmtaylor]

I've used FW a handful of times.  I've never done anything to try to determine if I like it better.  I know some people really like it - particularly for german styles that are less hop heavy.

I find you'll get excellent results from the German noble hops if boiled for 60 minutes -- the FWH thing makes no difference.  These hops just love a long boil time.  But we digress.

[S. cerevisiae]

For anyone who is interested, here is a paper involving the reaction kinetics related to the isomerization of alpha acids: http://pubs.acs.org/doi/pdf/10.1021/jf8004965

Table #2 on page 6411 is interesting.

[dilluh98]

Good find, Mark. Based on this, an 80 C (176 F) whirlpool for 20 min (approximately my standard whirlpool conditions) gives ~8% total acid isomerization of a 60 min boil for the same commercial non-isomerize hop extract. Oversimplifying, you could plug in the value for 1 oz at 60 min boil, take 1/10th of that IBU and that's about what you'll get for 1 oz of a 20 min whirlpool at ~175 F.

[denny]

I've used FW a handful of times.  I've never done anything to try to determine if I like it better.  I know some people really like it - particularly for german styles that are less hop heavy.

I find you'll get excellent results from the German noble hops if boiled for 60 minutes -- the FWH thing makes no difference.  These hops just love a long boil time.  But we digress.

And I disagree.

[neddles]

I do not include the hops in a hop stand in my IBU calculation.

I may start doing this as well.  It's only in the last year or so that I started doing "hop stands" by adding hops after chilling the wort to ~150F and then adding some hops in and letting it rest like that for 30 mins.

I'm drinking a beer right now that I had calculated to about 45 IBU but it doesn't seem like it's quite there.  the hop stand hops were calculated to contribute about 7-8 IBU.  Maybe that's not enough or maybe my AA estimates were off but the beer seems like it could use a little more bitterness.  I still like it but next time I'd be inclined to add a few more hops at 60 mins.

Morty, it is my understanding that you are getting no isomerization at 150F so your lack of bitterness should probably be accounted for elsewhere, no?

[klickitat jim]

Good find, Mark. Based on this, an 80 C (176 F) whirlpool for 20 min (approximately my standard whirlpool conditions) gives ~8% total acid isomerization of a 60 min boil for the same commercial non-isomerize hop extract. Oversimplifying, you could plug in the value for 1 oz at 60 min boil, take 1/10th of that IBU and that's about what you'll get for 1 oz of a 20 min whirlpool at ~175 F.

If you use the same system, method, and grist/OG/hops as in the study. I think whirlpool hopping is one of those things where a brewer's personal experience is far more valuable than tge results of a study. A % of utilization from a study is fine for a starting point. But be open minded and ready to adjust to your own experience. For me, 30 minutes at 170F with my tangential whirlpool going the whole time... its 0%

Another glitch is that calculated IBUs rarely match the actual IBUs when brewers send the actual beer in for a test. So, even with boil additions its just theoretical. You still have to taste and be ready to adjust.

[evil_morty]

I do not include the hops in a hop stand in my IBU calculation.

I may start doing this as well.  It's only in the last year or so that I started doing "hop stands" by adding hops after chilling the wort to ~150F and then adding some hops in and letting it rest like that for 30 mins.

I'm drinking a beer right now that I had calculated to about 45 IBU but it doesn't seem like it's quite there.  the hop stand hops were calculated to contribute about 7-8 IBU.  Maybe that's not enough or maybe my AA estimates were off but the beer seems like it could use a little more bitterness.  I still like it but next time I'd be inclined to add a few more hops at 60 mins.

Morty, it is my understanding that you are getting no isomerization at 150F so your lack of bitterness should probably be accounted for elsewhere, no?

I was calculating it as some bitterness that perhaps I wasn't getting.

[HoosierBrew]

If you use the same system, method, and grist/OG/hops as in the study. I think whirlpool hopping is one of those things where a brewer's personal experience is far more valuable than tge results of a study. A % of utilization from a study is fine for a starting point. But be open minded and ready to adjust to your own experience. For me, 30 minutes at 170F with my tangential whirlpool going the whole time... its 0%

Exactly, Jim. It's good info but it's apples-and-oranges unless you use the same system. For me I don't own a pump, so my 'whirlpooling' is walking by the kettle every few minutes and stirring it thoroughly. I'm pretty sure that's less efficient than a brewery's ability to whip the wort into a giant whirlpool. I just trust my senses and go with it.

[dilluh98]

I agree that your personal preference is what matters most but for a variety of reasons, sometimes brewers want a handle on the numbers. Mark gave a good basic reference for those interested. It gives a starting point for those who have little or no experience with whirlpool hop additions.

[denny]

Another glitch is that calculated IBUs rarely match the actual IBUs when brewers send the actual beer in for a test. So, even with boil additions its just theoretical. You still have to taste and be ready to adjust.

That hasn't been my experience, Jim.  Every beer I've sent to be tested was within 1-2 IBU of the estimate from Promash using Tinseth calcs.

[hopfenundmalz]

Another glitch is that calculated IBUs rarely match the actual IBUs when brewers send the actual beer in for a test. So, even with boil additions its just theoretical. You still have to taste and be ready to adjust.

That hasn't been my experience, Jim.  Every beer I've sent to be tested was within 1-2 IBU of the estimate from Promash using Tinseth calcs.

None of the calculators take into account the iso-AA saturation, so anything they predict over 70 or so is too, high, let alone higher than that.

[klickitat jim]

I agree that your personal preference is what matters most but for a variety of reasons, sometimes brewers want a handle on the numbers. Mark gave a good basic reference for those interested. It gives a starting point for those who have little or no experience with whirlpool hop additions.

Totally agree. Its when you are told your experience is wrong because a study says so that the rub exists. On this one, study stuff for a jump off point, then run with what your experience dictates.

[klickitat jim]

Another glitch is that calculated IBUs rarely match the actual IBUs when brewers send the actual beer in for a test. So, even with boil additions its just theoretical. You still have to taste and be ready to adjust.

That hasn't been my experience, Jim.  Every beer I've sent to be tested was within 1-2 IBU of the estimate from Promash using Tinseth calcs.

Hmm, well there ya go. Usually folks report them being off. I guess it can also be acurate sometimes

[denny]

Another glitch is that calculated IBUs rarely match the actual IBUs when brewers send the actual beer in for a test. So, even with boil additions its just theoretical. You still have to taste and be ready to adjust.

That hasn't been my experience, Jim.  Every beer I've sent to be tested was within 1-2 IBU of the estimate from Promash using Tinseth calcs.

None of the calculators take into account the iso-AA saturation, so anything they predict over 70 or so is too, high, let alone higher than that.

Yep.  The beers I've had analyzed were in the 35-60 range.