recommendations for swing temp range?

[Mylo]

OK, I finally have the ability to control my fermentation temps. I have a 14.8 CF chest freezer, and a Ranco controller. Woot!





What do you guys use for your swing temp range? I have my sensor taped to the carboy and wrapped with bubble wrap. I currently have it set for 2 degrees. I have to use a reptile heater ( thanks, Gucci ) to keep the whole thing warm, considering it is a one stage and it will be below ale temps in my garage for the next 2-3 months. Do you think that is a good balance between compressor cycling and yeast toleration?


Mylo

[BadRock]

Maybe instead of leaving the reptile heater on full time you could put it on a timer and kick it on for 15mins. every hour or so. This would reduce the amount that the compressor had to run but it would also keep the temp up.

General rule of thumb for any motor is no more than 4 "starts per hour" It is the high inrush current that generate massive amounts of heat and leads to premature failure.

[Mylo]

Excellent idea, BR. However, I don't think it is that big of an issue right now, with the ambient temp in the garage being what it is. Before I put the freezer on the control, I put the reptile heater in the bare freezer just to see what the maximum temp it would get to in there. It was only 68 or so, and I'm trying to keep it on 65. If the garage warms up, I will do the timer trick. So, I guess you think that a swing from 65-67 is no big deal for the yeast?


Mylo

[BadRock]

It'll be fine, you have enough thermal mass in a 5 gallon carboy, the little yeasties will never even feel the swing!

[DannyW]

FWIW when I strap my probe to the fermenter and insulate it like you did I set the differential to 1F. If I leave the probe hanging in the air, I set it to 4F.

One other tidbit - If you are trying to crash cool something, definitely strap the probe to it. I once left the probe in the air and monitored the temp of the cornies with a thermometer strapped to the side and it took like 4 days to get down to the set temp! With the probe strapped to the corny it only took a couple of hours. I guess it's because the freezer doesn't have a fan to move the air around like a fridge and the boundary layers hang around a long time.