Thermowell, thermal grease

[30Bones]

Setting up my new 3V electric brewery and all my temp probes are tri-clamp RTD. For my MT I will be using a longer temp probe and therefore using a 5" tri clamp thermowell with a 1/2" threaded external female bung. Threading a RTD temp probe into that. I was told I need to get some thermal grease to take up the air void and give a more accurate reading. It seems there are a lot of options and most focus on heat sinks. I just want to get the right stuff. This is a secondary temp location. The kettle also has an analog dial thermometer as well as the HERMS temp.

 

[Vale71]

Just get the cheapest silicone-based thermal grease you can find. You don't really need the expensive silver paste used for CPUs just for temp measurement.

 

[30Bones]

Thanks. Going to run a test run with just water tonight and see how the digital and analog probes read. Plus it's a nice practice session to learn how this all works compared to my old eBIAB

 

[doug293cz]

Your biggest issue will be getting the thermal grease down into the closed end tip of the thermal well, as this is the only spot that will do any good. The temp probe is only sensitive at the tip. Leaving out the grease is an option if you are willing to accept slower response to temp changes. If you don’t get the grease down to the tip, it is the same as not having any grease.

Slower response should be acceptable for measuring mash (unless doing step mashing with high ramp rates, but fast ramps are more difficult with HERMS) or HLT temp, as they change slowly anyway. You need fast response in a RIMS, but you aren’t using one of those.

Brew on

 

[30Bones]

Thanks, I did a test run with just just water Friday and the probe in the thermowell (no grease), analog thermometer also in a thermoswell (no grease) as a therma pen in the water all read within .3 degrees. Well the analog was not easy to tell how close it was, but it was as close as my eyes can tell. I think for now I am just going with it as is. Ramping temps will never be a fast process on a HERMS in my experience. I have a rather large-ish coil at 5/8"x50' too. LONG brew days ahead vs my old BIAB setup, but I hope it's worth it for more consistency.