OK, I decided to give DH recirculation a try. Unfortunately, I missed noting the schedule described above, so after dumping yeast and with a very heavy DH load, I recirculated for 8 hours at a 50% duty cycle (i.e. each hour the pump was on for a half hour). YUCK! Not only over hopped but way over extracted. A 10G dumper.
From I what I've found in various descriptions, it looks like I can get good extraction in about 6-8 hrs, even at very low temps, maybe 40*F. So.... I'm thinking to try once more like this:
- Complete fermentation (fermenter will be at 10psi, 70*F)
- Chill to 40*F for 2days
- Drop yeast, raise temp to 55*F
- Add dry hops, about 50% of the amount I used previously (before recirculating)
- Recirculate for 1 minute per hour for 6 hours. Using a March pump I expect about 1-2 GPM flow when throttled some
- Reduce temp to 32*F for one day
- Transfer to kegs -- maybe filtering in the transfer
I want to reduce the risk of ruining another batch ahead of Thanksgiving festivities, so would appreciate feedback on this procedure from those who have been successful with DH recirculation.
Also, has anyone tried a similar method at different tempreatures that can comment on the sensory difference between, say, 40*F vs 65*F?