I’m very grateful to be able to brew with my Grainfather conical fermenter. I also have the cooling pump kit which I’ve found works very efficiently with my five-gallon water cooler and a couple of 2-liter pop bottles filled with ice. For my current batch, for the past ten days I’ve kept the internal fermenter temperature at a steady 68 (F). I’m wondering if there is any advantage in slowly increasing the temperature in the fermenter until bottling day. For example, I could increase the temperature to 69 for five days, then hold it at 70 until bottling day. Or, would it be best to just hold the temperature at 68 the entire time until bottling day? Thanks for your thoughts and perspectives.
I don’t think it matters a ton either way, especially if fermentation is done.
If you worry about wasting a ton of energy/effort on keeping it a bit cooler, I would say let it warm up to 70. Cooler temperatures are always better for beer storage, but honestly a 2 degree difference won’t be noticeable. You’ll lose a very tiny CO2 out of solution at warmer temperatures, and will get slightly different calculations on priming sugar as a result, but I think it’s really negligible to the point where I wouldn’t worry about it. You might get some noticeable differences if it’s not fermented completely, but this late in fermentation I don’t think it will be an issue.
So yeah, there are some technicalities where you could make an argument for keeping it cooler, but at the homebrew scale and given the 2 degree difference you’re talking about, I don’t see any reason in terms of beer quality to choose one or the other.
Like Andy has said, if fermentation is done there’s no point. I use the same fermenters. My process is to keep it at 63F (for most ales) for 4-5 days, bump it up to 70-72 for maybe 3 days, then crash to 35F. I raise the temp to ensure fermentation is done. But if your fermentation is already over, there’s no point.
Thanks a lot, Andy and Denny, for your helpful replies. I’m glad to know more about your process, Denny, when using the Grainfather conical. I’ll try your temperature formula next time I brew an ale. I’m brewing a lager next time and trying to see if I can keep the temp at around 44 or less for about three weeks. If I change out the frozen pop bottles about every 12 hours I think I can do it. One last question: when you cold crash your ales to 35, how long do you hold it at that temperature?
FWIW, I’m using the glycol chiller. Usually 2, maybe 3 days, then dry hop for 2 more days
Thanks again, Denny. Wish I could afford the glycol chiller. I couldn’t generate a couple of days at 35 degrees with my primitive cooling pump kit.