Whirlpool/Steeping experience

[Cisco]

I'm getting ready to brew my first batch on a 3 1/2 barrel system. I've made test batches on my pilot 10 gallon system and I'm ready to start sizing up my recipes. On my pilot system I use whole hops and have a boiler screen that filters the wort on the way out and I usually add my last hop addition 20 to 15 min. before end of boil. My 3 1/2 barrel system can only use hop pellets and therefore I have to possibly move my normal late hop addition to the whirlpool/steep step. What concerns me is the hop utilization during the 20 min. whirlpool and 20 min rest before moving the wort through my wort chiller. I see that BS2 has a Whirlpool/Steep option for hop additions but how accurate have you found this to be? All advice is appreciated!

[brewfun]

It depends.

Accuracy for WP hops is empirical. That is, all of the calculations and assumptions are based on observations, not studies.Why? There simply is scant research on WP hopping. On top of that most of the research is on wort that's under 50 IBU and what's there shows that simple IBU calculations are not sufficient for the needs of modern craft brewing. Flavor development is still the art of the brewer.

You can assume at least 20% utilization for WP additions at the duration you've laid out. Most utilization happens in the first 20 to 30 minutes of exposure and even then, it's Cohumulone that isomerizes first. CoH is considered responsible for "coarseness" in bittering perception, but there are other contributors, as well.

Certainly, the quickness of Alpha Acid and Oil separation from the hop material is faster with pellets. So, that's a good reason to place their addition further down the process.

The main thing is consistency with your commercial batches. That may take a couple of batches to dial in. Once dialed, it'll be a piece of cake for you to know what to add and when, with any new recipe. In the meantime make a batch with all pellet hops at the same addition times. Compare that to the whole hop version  and decide the appropriate adjustments.

[YanezInc]

I think, as brewfun said, that it is mostly about experience. I reckon you will get a higher content or at least more consistent extraction out of your pellets. It might not be as attractive or romantic maybe but I dont see why you would need to add them later in your process.

What we normally do when we do those type of changes is perform small experiments... it might not be scientifically accurate most of the time but at least we get an idea of what we are about to do... in such a fashion that in this particular case we would prepare two different trials following your hopping dosage on both cases at the two different times on lab sized manageable volumes (it could even be with plain brewing liquour) so that in the end you get an idea of the impact that the change your about that carry might result into in your wort.

In any case I would think of adjusting quantities when switching whole leaf hops to pellets... but that is just my assumption... again... I would try to at least carry a couple of small runs with stock saved wort or plain water to see what the impact is.