Location for temp sensor

[nwbrewing32]

Hey Everyone,

I am buying a FermWrap to keep the temperature up on my fermenter in the cellar.

I have a temp. controller with a waterproof sensor, but I'm wondering if I can just tape the sensor to the side of the fermenter.

Would this be okay, or do I need to have it inside the fermenter touching the beer?

Thanks!

 

[day_trippr]

Given it would be difficult to thermally isolate a contact probe from the heat wrap I suspect the best performance will require a thermowell...

Cheers!

 

[emcfarden]

[Edit] I misread your post, I assumed you were talking about a refrigerator instead of just a carboy with fermwrap

I keep my temp sensor in a gallon jug of water in the fermenter. It acts as a thermal mass similar to the beer, so the compressor doesn't cycle on/off as frequently. I don't have to worry about taping/insulating it or messing with a thermowell.

It's especially convenient if you have two or more different beers fermenting in your vessel, you don't have to choose which one has the thermowell or worry about transferring it when one is done. I usually set the temperature a couple degrees lower than what I want the beer to be since the fermentation activity is generating some heat.

 

[Weezy]

The only problem with a separate thermal mass is that the temp controller isn't going to react nearly fast enough to changes in the wort temp. It could be a day or more before a gallon jug of water will rise to match the wort temp.

Even the cheapest temp controllers have delays in them to shield your compressor.

 

[Sadu]

Another trick is to put your fermentor inside a swamp cooler in the fridge (or in your case the cellar). Probe goes in the swamp cooler.

This has the advantage that the fridge won't cycle every time you open the door, plus you don't have to have the probe in the beer. I find the acidic beer damages the probes and they lose accuracy. Thermowell would be better, but I ferment in plastic and are concerned about a thermowell making it harder to sanitise.
The thermal transfer between the swamp cooler water and the beer in the fermentor is very good, plus you can heat using a cheap aquarium heater which I find more convenient than other methods.