Should the late addition portion of a recipe be altered based on immersion, counterflow, whirlpooling techiques?

Question

When it comes to late addition hops (or other late aeromatics), it seems to me that there might be significant differences in aroma extraction / utilization as the brewer executes different chilling techniques. I presume here that late additions are added and remain in the wort as long as possible. All these times depend on each person's chilling water temperature, equipement,etc, so we are forced to generalize about times, but the effect of times and temperatures are what we're trying to parse out in this question.

• Immersion - All of the wort is available and making contact with the late addition ingredient as the wort goes from boiling to pitching temperature. This might happen over 15 to 40 minutes (whatever). The point is that for the early part of chilling, the temperature is high, and the later part of chilling, the temperature gets colder and less likely to extract any aromas (also less likely to drive off any aromas).

• Counterflow w/gravity - Initially all of the wort is making contact with the late addition ingredient, and the wort stays pretty hot the whole time since chilling happens outside of the boil kettle. Gravity feed through a counterflow chiller might happen over 15 to 20 minutes (whatever). So the aeromatic ingredient is in the hot wort the whole time.

• Counterflow w/pump - Same as with gravity, but the times would be shorter.

• Whirlpool & Counterflow w/gravity - This is actually my setup. I like to whirlpool and I drop a stainless steel screen down after the hops settle out in the middle of the boil kettle. This keeps the hops from leaving the kettle when I open the valve into the counterflow chiller. In this case, a flameout addition would be making contact first during whirlpool settling (15 minutes), plus while chilling (another 15 minutes).

• Hopback with chiller - the theory here is that the hot wort allows extraction of the aromatic oils which are contained, due to the closed system, followed by a fast chill which locks the aromatics in before they dissipate.

The question is, should the recipe be altered based on the techniques mentioned above, and what alterations should be made for the different techniques.

Answer 1

You do need to adjust the recipe for process. However, I am sure what you are looking for is an adjustment rule to convert another brewers recipe to your process. Well there is no hard rule for that as everyone's process is different.

You need to understand your system, brew the recipe once as is. Then re-brew the recipe with changes in hop amounts to dial it in to your needs.

Of course if you know the recipe was made with one method that is significantly different from yours, you'll need to rely on your own experience to make an adjustment.

This is where the art of being a brewer becomes apparent. The more you brew and the more you understand your system, then you CAN make adjustments to recipes to make them come out as intended. Even when the recipe was someone else's to start with.

Answer 2

My answer would be to know your own brewhouse and adjust as you see fit. Home brewing is sometimes more of an art than a science - aromatics is a good example of that where precise control would require some kind of pre-analysis of the aromatic compounds, their rate of uptake and rate of volatilization. Even if you could nail it down to hard figures, you still have the uncertainty of how much aroma is lost during primary fermentation, requiring more experimentation and analysis. And finally, what one person perceives as excessively aromatic, the next may consider not to be.

So keep it simple - use what you have and if the aroma isn't to your liking, adjust quantities accordingly.

EDIT: To answer Graham's request about my own process: My current process does not produce as much hop aroma as I would like, so I tend to up the late additions by 25-50% and move them closer to flameout. In the coming months I will be investigating using a hopback to see if I can use less hops for the same aroma. I will also investigate partial chilling via an IM coil to see if that helps lock in more aroma.