Yeast Temp Range & Heating/Cooling Differentials

[pvburton]

I'm changing my fermentation setup to use dorm fridges, each controlled by an ITC-308 and I have a couple of small questions. This is in my attached garage and I expect temperatures to be below room temperature for most of the year. Also, I plan to go w/ a compressor delay of 5 minutes as this has been working well thus far for my older setups.

I plan to tape the probe to the side of the vessel, so I expect actual temperatures inside will be slightly higher during primary fermentation. Anybody have data on how much higher I should expect this to be?

If I want to keep temperatures towards the lower end of my yeast's range, should I care if the heating differential allows the temperature to drop below that range?

Also, what is a reasonable difference between both modes so that they don't thrash back and forth between heating & cooling needlessly?

 

[micraftbeer]

I've seen the temperature during active fermentation climb by a couple of degrees in a fermentor sitting in an open room, so I would expect in a dorm fridge, you'd see something greater. You didn't say if you're throwing in a heating bulb or something to add heat?

With your heat/cool coming from the air outside your fermentor, and your temperature probe outside your fermentor, I'd be concerned that you'll be cycling fairly quickly and more importantly, not really getting the bulk of your fermenting beer to the temperature you want. Is your fermentor a type that will work with a thermowell? Probably similar items out there like this: https://www.homebrewing.org/Stopper-Thermowell_p_1733.html

I'd find a way to get the temperature probe inside your beer, turn down the fridge controller to something less than max cool, and iterate your way to ideal settings. If you can't/don't want to go the thermowell route, then I'd try to find a way with use of big blocks of foam to try to isolate your temperature probe as much as possible from the air temp inside your fridge and get it in contact with the side wall of your fermentor.

During the beginning of your fermentation is where things will be most active and have the most temperature rise. That's the portion where you'd be hurt with a temp sensor on the outside.

 

[JONNYROTTEN]

I keep the compressor on 10 minutes. THey say it helps save the fridge and an extra 5 minutes makes no difference.
I keep the temp difference at 1 deg so the fridge doesn't have to run as long and overcool the fridge to bring down the liquid temp.
I use a light bulb to heat but any heat source will work.

The internal temp wont rise during fermentation if you have it under temp control...the reason you have a chamber...obviously
It keeps everything within one deg of what you want. Cant ask for more than that