Hop utilisation at whirlpool - seem high

MeemoNZ

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Hi,

Im putting together a recipe with hops at the whirlpool, I've put hops into the recipe, but the IBU seems wrong, they seems to perfectly reflect the AA of the selected hops:
Screenshot 2020-12-09 at 10.20.10 PM.png


Comparing this with another recipe builder (from GrainFather) shows the below:
Screenshot 2020-12-09 at 10.26.55 PM.png

*note GF don't differentiate between hopstand and whirlpool.

The summary is that BrewersFriend estimates a recipe at 44 IBU and GrainFather estimates the same recipe at 25 IBU... hmmm.

Is there an issue with the IBU's shown in the BF recipe?

Thanks
Andy
 
I'm not a big fan of the way whirlpool utilization is calculated at this time, as it's attempting to treat whirlpool with a different flat utilization value instead of treating it as a percentage of it's boil IBU for the same time period.

In many scenarios, especially at low time period, this can end up with a whirlpool addition providing more IBUs than a boil addition for the same time period, which is of course nonsense.

The system we have now, and all other brewing software use at this time, also assumes that boil additions magically stop isomerizing at t=0, providing zero additional ibus during a whirlpool process and only the hops listed as "whirlpool" add additional ibus...

A bit of light reading for an IMO, better model that I'm hoping we switch to at some point.
https://alchemyoverlord.wordpress.c...-ibu-measurement-especially-for-late-hopping/

Their online calculator can be seen here.
https://jphosom.github.io/alchemyoverlord/

With that said, all IBU formulas are very rough approximations. Tinseth for example had a 25-30% experimental uncertainty IIRC.
 
I'm not a big fan of the way whirlpool utilization is calculated at this time, as it's attempting to treat whirlpool with a different flat utilization value instead of treating it as a percentage of it's boil IBU for the same time period.

In many scenarios, especially at low time period, this can end up with a whirlpool addition providing more IBUs than a boil addition for the same time period, which is of course nonsense.

The system we have now, and all other brewing software use at this time, also assumes that boil additions magically stop isomerizing at t=0, providing zero additional ibus during a whirlpool process and only the hops listed as "whirlpool" add additional ibus...

A bit of light reading for an IMO, better model that I'm hoping we switch to at some point.
https://alchemyoverlord.wordpress.c...-ibu-measurement-especially-for-late-hopping/

Their online calculator can be seen here.
https://jphosom.github.io/alchemyoverlord/

With that said, all IBU formulas are very rough approximations. Tinseth for example had a 25-30% experimental uncertainty IIRC.

Thank you, understand and yes agree the current maths don't add up. GrainFather have a new interesting approach of working out the IBU / min that decreases over time based on temp decrease.
Screenshot 2020-12-10 at 8.57.53 PM.png


Makes alot more sense though its all a guessing game and system dependent.
 
In my opinion, when it comes to pellet hop utilization math modeling the Tinseth method is not even in the ballpark. The only guy I'm aware of who has been getting a handle on pellet hop utilization is Chemistry Professor Christopher S. Hamilton, Ph.D Hillsdale College. His presentation on "The Effect of Temperature and Alpha-Acid Concentration on Hop Utilization in Wort" as given at the EBC Hop Symposium in Nuremberg, Germany, September 2018 indicates that pellet hop utilization is realized much more quickly within the boil than for whole hops as modeled by Tinseth. In a podcast a few years ago Tinseth stated that he never once tested a pellet hop, and as to his model and pellet hops he stated: "All bets are off". The conception of 10% x Tinseth = pellet hop IBU's is a farce. A look at the right most column on page 12 of Dr. Hamilton's PPT overview summary (linked below) shows that by ~30 minutes into the boil a pellet hop has already delivered nigh on its full potential IBU load into the Wort. This is something that requires 60 to 90 minutes for whole hops. If you want to get pellet hop modeling correct, this man is whom you should approach. For pellet hops, merely extending Tinseth beyond the terminus of the boil and into cooling and continuing to apply 10% can't possibly be the correct approach.

https://hwcdn.libsyn.com/p/3/a/c/3a...07596711&hwt=b1453e73516b36a9c32adc81a84a3c22
 
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In my opinion, when it comes to pellet hop utilization math modeling the Tinseth method is not even in the ballpark. The only guy I'm aware of who has been getting a handle on pellet hop utilization is Chemistry Professor Christopher S. Hamilton, Ph.D Hillsdale College. His presentation on "The Effect of Temperature and Alpha-Acid Concentration on Hop Utilization in Wort" as given at the EBC Hop Symposium in Nuremberg, Germany, September 2018 indicates that pellet hop utilization is realized much more quickly within the boil than for whole hops as modeled by Tinseth. In a podcast a few years ago Tinseth stated that he never once tested a pellet hop, and as to his model and pellet hops he stated: "All bets are off". The conception of 10% x Tinseth = pellet hop IBU's is a farce. A look at the right most column on page 12 of Dr. Hamilton's PPT overview summary (linked below) shows that by ~30 minutes into the boil a pellet hop has already delivered nigh on its full potential IBU load into the Wort. This is something that requires 60 to 90 minutes for whole hops. If you want to get pellet hop modeling correct, this man is whom you should approach. For pellet hops, merely extending Tinseth beyond the terminus of the boil and into cooling and continuing to apply 10% can't possibly be the correct approach.

https://hwcdn.libsyn.com/p/3/a/c/3a...07596711&hwt=b1453e73516b36a9c32adc81a84a3c22
Wow this is great! First I've heard of Hamilton, a brief glance looks more in line with what I've seen experimentally.

I don't understand why none of the major players in the industry aren't backing some basic research into something so fundamental. It's not even a complicated experiment to perform, just need a lab with the testing equipment.

My sister actually has a cottage in Hillsdale a few minutes away, I might need to make a stop next time I'm driving through...
 
Also notice that within 1 minute of boiling a pellet hop has already liberated nearly 60% of all of its potentially liberatable IBU's. Utilization at 1 minute is 19.9%, vs. roughly 1.33% utilization for pellets boiled 1 minute via Tinseth plus 10%.

Also, Tinseth when following Hamiltons 10 Plato and boiling 1.5L down to 1L with 1 gram of 13.3 AA Citra predicts ~45 IBU's at 60-90 minutes whereas Hamilton's experiment discovered an actual 66-69 IBU's. That's ballpark 45-50% more IBU's for pellets than Tinseth plus 10%.

Tinseth is effectively useless with pellets.
 
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Pages 19 through 22 of "The Effect of Temperature and Alpha-Acid Concentration on Hop Utilization in Wort" reveal that pellet hop utilization at typical post boil whirlpool temperatures after 20 minutes is roughly 60-70 percent of that accomplished via boiling pellets for 20 minutes. That's a lot of IBU contribution. Likely well more than most would imagine. And at 10 minutes the data isn't very far behind 20 minutes. Call it ballpark 50% of IBU yield via boiling. But remember also that which has been discussed above and factor in that pellet hops when boiled release IBU's both much faster and at a much higher level of output than for whole hop derivations.
 
Pages 19 through 22 of "The Effect of Temperature and Alpha-Acid Concentration on Hop Utilization in Wort" reveal that pellet hop utilization at typical post boil whirlpool temperatures after 20 minutes is roughly 60-70 percent of that accomplished via boiling pellets for 20 minutes. That's a lot of IBU contribution. Likely well more than most would imagine. And at 10 minutes the data isn't very far behind 20 minutes. Call it ballpark 50% of IBU yield via boiling. But remember also that which has been discussed above and factor in that pellet hops when boiled release IBU's both much faster and at a much higher level of output than for whole hop derivations.
Yes that was my immediate takeaway as well, it seems that a significant portion of the bitterness vs time curve for whole hops had to do with breaking down the hop matter and making the oils available / soluble. Since T90 pellets are very easily broken down, the isomerization begins almost immediately.
 
Yes that was my immediate takeaway as well, it seems that a significant portion of the bitterness vs time curve for whole hops had to do with breaking down the hop matter and making the oils available / soluble. Since T90 pellets are very easily broken down, the isomerization begins almost immediately.

It would be amazing if you could make contact with Professor Christopher S. Hamilton and see if he has even more to offer. Perhaps Brewer's Friend can become the first to model pellet hops based upon his work and that of his students.
 
If I'm reading you right here... Using Pelleted hops would shift the time of insertion towards the end of the boil time for the same isomerization level?


upload_2021-1-13_12-35-40.png


Is it just the calculation of isomerisation time that is in question here or would there be some other flavour additions - possibly unwanted - by leaving in the pelleted hop product in the wort for longer. Is there a taste issue here too?
Forgive me if asking a newbie question. I love the science here - want to know more.
 
If I'm reading you right here... Using Pelleted hops would shift the time of insertion towards the end of the boil time for the same isomerization level?


View attachment 13677

Is it just the calculation of isomerisation time that is in question here or would there be some other flavour additions - possibly unwanted - by leaving in the pelleted hop product in the wort for longer. Is there a taste issue here too?
Forgive me if asking a newbie question. I love the science here - want to know more.
Good question. In the context of IPAs, I have been moving bittering hops to 30 minutes and no other additions until WP. For IPAs with all high AA hops, I have nothing going in the boil with bittering hop addition at FO and cooling immediately to WP temp. Easy to get 50-60 IBUs. One of our local commercial brewers that specializes in pales and IPAs only uses hop oil in the boil to minimize green matter and the flavor and aroma hops all in the WP. At this point it’s really about trial, taste, error, repeat. I’m good with that. If brewing worked perfectly like paint-by-numbers, the end product would likely suck equally.
 
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If I'm reading you right here... Using Pelleted hops would shift the time of insertion towards the end of the boil time for the same isomerization level?


View attachment 13677

Is it just the calculation of isomerisation time that is in question here or would there be some other flavour additions - possibly unwanted - by leaving in the pelleted hop product in the wort for longer. Is there a taste issue here too?
Forgive me if asking a newbie question. I love the science here - want to know more.
I'm not aware of any additional flavor/aroma compounds that are extracted at longer times, but the flavor profile definitely changes as some hop oils are more volatile than others. Which is one of the reasons why hops are so complicated, it's not just that a 15 minute addition produces MORE flavor than a 45 minute addition, leaving bitterness aside, but that the actual flavor profiles are different.
 
I'm not aware of any additional flavor/aroma compounds that are extracted at longer times, but the flavor profile definitely changes as some hop oils are more volatile than others. Which is one of the reasons why hops are so complicated, it's not just that a 15 minute addition produces MORE flavor than a 45 minute addition, leaving bitterness aside, but that the actual flavor profiles are different.
Add to that the 60 minute addition, contrary to popular notions, does contribute flavor... Hops are the most difficult and least understood aspect of brewing, far more so than water.
 
Add to that the 60 minute addition, contrary to popular notions, does contribute flavor... Hops are the most difficult and least understood aspect of brewing, far more so than water.
And that there are synergistic properties of hop oils and thiols where the combination of different hops can have flavor profiles that are not present in the individual hops when used separately.
 
Now it's getting more complicated... I think I will have a beer and read up
 
And that there are synergistic properties of hop oils and thiols where the combination of different hops can have flavor profiles that are not present in the individual hops when used separately.

And that was one of the hardest things to me to "get" at first. I made a lower ABV Arrogant Bastard clone, calling it "Lil' Bastard". I went with mostly centennial hops and lots of them but used some warrior I believe to increase the IBUs.
Now, I have used centennial with chinook and cascade (the classic C hops) with great results; but I remember saying that I hated this beer- it "tasted like effing flowers!" I know centennial has citrus/floral qualities but the combo I made really made it super flowery until it aged quite a bit. Still had very strong floral notes, though!
 

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