Recirculating during Conical Dry Hop - am I nuts?

[goodolarchie]

I'm new to conicals, but finally got myself a Chronical BME, and excited to have so much more control over the fermentation and exposure to oxygen. I'm thinking ahead to equipment and hop schedules, particularly for very juicy IPA dry hop additions sensitive to oxidation.

How does this program sound for aiming at a ~2 week turnaround?

(After Brew Day) - transfer Wort to Fermenter, reach 65ºF, pitch ale yeast.
Day 2 - free rise to target temp.
Day 3 - Sample indicates last ~10% of attenuation, time for small first hop addition. No need to purge CO2 with little headspace and fermentation active, but it wouldn't hurt...
Day 7 - Fermentation is complete, beer is at its diacetyl rest temperature (let's say Imperial Juice at 73ºF). Force tested for acetolactate/diacetyl. Cold Crash with ice bath circulation overnight.
Day 8 - Yeast and first dry hop has dropped out, dump using sight glass from the dump port until it clears up. Second dry hop addition, purge with CO2 and PRV. Beer rises back to ~63ºF in roughly 24 hours. The cooler temperature is to prevent a re-fermentation.
Day 9 - Hops are settling, need to circulate. Connect sanitized line from dump port, to sanitized pump, up sample port, which creates a bit of a whirlpool or tank circulation. This can be run periodically, perhaps every morning and night.
Day 10-12 - same recirculation schedule.
Day 13 - fining if applicable, final cold crash
Day 14 - removal of hop matter and anything remaining that can drop out. Purge, closed pressure keg transfer, carb
Day 15+ - enjoy!

 

[charliethebum]

How do you plan to recirculate without introducing o2? Seems like a big risk without much reward, but if you end up trying it let us know how it turns out

 

[goodolarchie]

How do you plan to recirculate without introducing o2?

Yeah good question. One solution would be to actually purge the pump line with co2 and gravity (say, if there's 2 ft input tubing - pump - 3 ft output tubing). Hung vertically, the input line is purged from the priming valve on the pump (sitting at hip-height) with 1-2 psi of CO2, which would be done first, then any remaining oxygen in the output line would be purged out of a valve on its end, with both sealed and disconnected from gas.

At that point, priming the pump with tank beer will push only CO2 out the relief valve, and push co2 into the fermenter at the output end as it "burps", which isn't a big deal as it has its own PRV set to 2 PSI. Any oxygen left in the mix would be pushed out of the conical's PRV at this point.

The upside of this would be it takes very little CO2 to purge the volume in 5 feet of tubing and the pump, the downside would be potentially the need for additional gas fittings and keeping everything airtight in this process.

Another solution (K.I.S.S.) would be to fill the system with a starsan solution, and have the pump on its lowest setting push a little bit of beer out until no bubbles remain. I don't love this though because that first beer contains all the hop matter you want circulating!

Lastly, do away with the need to recirculate by just using a dry hopper. I don't love this because I never get as good aromas compared to simply immersing pellets in primary/secondary, and I still think it requires some circulation to get the best surface contact.

Is there another option I haven't considered?

 

[charliethebum]

Both seem like viable options as long as your pump doesn't cavitate any. The starsan flush seems like the easier option. I personally get great aroma with a loose dryhop in the conical and then racking onto a smaller keg hop charge, never would have considered recircing my fermenter but who knows might be mind blowing