How to better insulate the temperature probe?

[Belgian Samurai]

Hi,

I use an Inkbird temperature controller. This is my 2nd pressure ferment brew. The first time was with a heat lamp. This time I'm using a FermWrap, but I'm having issues with my temp reading between the inkbird controller and the temperature of the liquid. One thought is I don't have good isolation between the temp probe and the FermWrap, this the heat from the FermWrap is reaching the temp probe. The FermWrap does not wrap all the way around the keg, so there is about a 12cm/5in margin, which is where the temp probe is located. The liquid temp is 5⁰C cooler than the Inkbird is reading. Any suggestions? To deal with this short-term, I just raised the set temp on the heater by 5⁰, but I'd really like to get this sorted out. I'm currently just using a piece of foam insulation I found in the basement, which can be seen between to two sleeves.

Alternatively, there is the $65 keg lid with a 12" welded thermowell, but that is my last resort if I can insulate this temperature probe for free.

Thanks in advance!




In this picture:
6.1 gal Torpedo keg
40v FermWrap
2 x 2.5gal keg sleeves
SPUNDit 2.0
Picnic Tap 2.0
FLOTit 2.0

 

[hotbeer]

Putting temp probes on the outside of a FV or other tank works somewhat to guess at the liquid temp inside. But if you add a heating blanket to that mix, then all you are going to get is the temp of the heat from the mat being conducted through the metal and eventually into the liquid inside. So even less of a guess as to what is happening inside.

You really need to figure out a way to get a temp probe inside. Either with some sort of thermowell or a Tilt, Rapt Pill or Ispindle hydrometer that will also tell you the SG as well as temperature. The Rapt Pill actually has ways to be used with other of Kegland's stuff so it's info can be used to turn on and off things like heat. Don't know if someone with programming smarts can do their own thing with it, but they do give you some of the API's that might allow that.

Otherwise just put as much foam insulation between the heat wrap and the probe as you can while letting the probe touch the side of the FV or keg and just accept that it won't be what the temp of the stuff inside is necessarily.

You might have to widen your parameters on the Inkbird until everything stabilizes. Then you can narrow them up some.

 

[DuncB]

I'm not familiar with the fermwrap, does it cover all of the keg and then that is insulation all over the top of it?

I use a heating belt on my fermenters , the temp probe for the brewpiless I stick on with a big blob of blu tack and then put foam pad from a sleeping mat over the top of this held on with a bungee. The heat belt is a little above the temp probe and I have only the cable to the heat belt in the vicinity of the probe not the heating part.
I find that this temp probe is close to the temperature that the ispindel records floating in the wort.

When fermentation slows or finishes you do get more stratification as there's no churn so can be a degree warmer at the top than lower down.

During ferment stage I rarely even plug the heat belt in as there is heat produced and actually cooling is needed so the belt only gets plugged in for the diacetyl rest boost. Although if using kveik I find the heat is needed earlier.

 

[Belgian Samurai]

Okay, I switched to some malleable foam insulation (it was probably some packaging material - hah) which did the trick beautifully! Here are some pictures of my approach.

Since I am using Trong's Picnic Tap 2.0, last night, I poured a sample directly from the keg and took a temperature reading. I then calibrated the temperature reading on the Inkbird ITC-1000 to match that reading. AND I only needed to adjust the Inkbird by 1⁰, so the foam insulation really did the trick! This morning, I checked both of those numbers again and they were spot-on! So, the replacement foam did the trick, isolating the temperature probe more efficiently and I didn't have to spend any money.

On a side note, another thing I love about this picnic tap is I can also poor a sample into a small jar (to shake out the carbonation) and take a gravity reading once it cools to room temperature.

Last but not least, I'm using a filtered floating dip tube, so don't have to worry about any particulates.

Thanks for the input and helping resolve the issue!

 

[DuncB]

@Belgian Samurai
Nice job, neatly done.