For those of you who use a firmwrap in conjunction with a temp controller, how do you attach the temp probe from the controller to the carboy? I am wondering if I am going to have to purchase the thermowell…and I am also wondering how one could use a thermowell and a blow off tube at the same time…pretty much impossible I assume. Thanks in advance for any insight into your process.
I use these thermowells : http://www.brewershardware.com/16-Stain … owell.html (for 6 gallon BetterBottles) – I also got my stirplate from there if you need one at 1/2 the price of NBs.
They go in the larger hole of these caps : http://www.northernbrewer.com/shop/3-5- … range.html
On the smaller hole, I use either an air lock that is attached with siphon tubing (since it won’t fit in the hole (rofl)), or just some tin foil over the opening. With all my ales, I just use tin foil unless i need to do a blow-off.
If you don’t want to invest in a thermowell, just insulate the probe with a sock and tape it on. It’s just as accurate, but a bit more annoying, which is why I use the thermowells.
Note that those caps may not work with glass carboys. You can drill a hole in your standard stopper to place the well.
Thanks for the great tips…the blow-off cap makes perfect sense! Just a few more questions. How does the temp sensor from the controller attach to the well? Also, have you tried to put an airlock into the smaller hole? Thanks again.
It doesn’t attach to the well, it goes inside the well. That’s why it’s called a well. 
At least, I’m talking about a standard Johnson A419 probe. It fits inside the well perfectly.
An airlock can’t be jammed in the smaller hole with relative ease. You need to put the air lock into a small piece of tubing, and attach the other end of the tubing to the small hole. Standard siphon tubing (3/16 ID) works well.
