You need to adjust your whirlpool hop utilization in your equipment profile settings.

 

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

 

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.

 

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.

 

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?




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.

 

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.

 

Now it's getting more complicated... I think I will have a beer and read up

 

You thought water was bad?

 

I'm working on it...