Temp Controller / Thermowell question

I've dug through the archives regarding temp controllers and it sounds like a digital is the way to go. I'm a little confused on placement of the temp probe. Some tape the probe to the carboy and insulate this locally to get close to wort temp and others recommend a Thermowell. I'm trying to figure out how a Thermowell could be used with a carboy? It seems like it would be inserted into the carboy to get wort temp directly but then a CO2 airlock couldn't be used. What am I missing here regarding the Thermowell location? Perhaps this is used with bucket type fermenter? I don't have any experience with them. Thanks ahead for helping...

i made some thermowells. took some ss tube, crimped and welded one end, flared the other with a brake flare tool. i then took a normal rubber stopper and drilled two holes in it, one for the thermowell and one for either an airlock or blow-off tube. works pretty well.

however, from my observation, the thermowell probe is always really close to the brewmometer sticker stuck to the side of my carboy. so if you just taped the probe to the side and covered it up with some folded paper towel, you'll probably get the same thing.

So the trick is two holes in the stopper one for Thermowell and a second for the airlock? Seems to make sense. I'd like to skip the Thermowell altogether unless there is a big gain in wort temp control.

i could have swore i did an experiment where I had a fermenting lager and monitored both thermowell probe and a probed taped to the side of the carboy....

well, i'm brewing a munich dunkel this weekend, i'll do it then!

Great I was thinking the same thing. Need a side by side comparison. I see a big gain by going from temp in general freezer air space to carboy temp but glass does have some insulating value so there is a difference just not sure how much.

Get some Plumbers Putty(Or Playdo if you have kids, although it can dry out, Plumbers Putty doesn't) and stick the thermocouple to the side of the carboy. Insulates, Attaches,and Works great.

I got my thermowell from Northern Brewer. It's just like the one built by motovrewer. I drilled a hole large enough to fit the stopper in a bucket lid so I can ferment in either a bucket or a carboy. Using a Johnson Digital Controller and the thermowell gives excellent temperature control.