Thermowell and Inkbird Probe

[TexasGuy]

I have a stopper with a thermowell, and in Inkbird probe (the small probe). Should I just stick the probe into the bottom of the thermowell, or should I fill the thermowell with water or star san solution?

Thank you for your feedback.

 

[BrewMan13]

I just put it in the thermowell without any liquid. Also changed out the standard probe for a longer one.

 

[IslandLizard]

Keep em dry!
For better contact you can probably use a thermal compound. Not sure how safe they are for the plastic probe and wires, though.

Is that a molded plastic probe or the small stainless tube one?
The former tend to get gooey/sticky in Starsan, the latter are not water tight, AFAIK, and will fail if water gets inside.

 

[sicktght311]

I found no matter what i did, whether it was dry, or thermal paste, i couldnt get an accurate reading with the temp probe when it came to my brewing system when i was using them in a thermowell. I ended up getting Amazon Crocsee 1/2" NPT pt100 probes, plumbing them directly into my kettles/in a tee, and wiring them up to a stereo jack for my Inkbird IPB16. Significantly better performance

 

[RPh_Guy]

the latter are not water tight, AFAIK, and will fail if water gets inside.

The stainless probes are waterproof.

I use a thermal paste in the well for my RIMS probe, but in a fermenter I wouldn't bother with that. In fact I wouldn't even bother using a thermowell in a fermenter, but whatever.

 

[sicktght311]

The stainless probes are waterproof.

I use a thermal paste in the well for my RIMS probe, but in a fermenter I wouldn't bother with that. In fact I wouldn't even bother using a thermowell in a fermenter, but whatever.

Why not a thermowell in a fermenter? I bought my fermenters with thermowells exclusively so i could use the inkbird to control my fermentation temperature.

 

[TexasGuy]

My Inkbird/Thermowell combo is reporting within 1 degree...but I've also not had any temp movement yet...

 

[RPh_Guy]

Why not a thermowell in a fermenter? I bought my fermenters with thermowells exclusively so i could use the inkbird to control my fermentation temperature.

The probe can easily be taped and insulated against the side of the fermenter.

 

[IslandLizard]

The probe can easily be taped and insulated against the side of the fermenter.

I too find that the most effective position for the ferm chamber probe. I use 6.5 gallon plastic bucket fermenters. Occasionally plastic or glass carboys.

That placement measures the temp of the outside of the fermenter. It's a place where 2 main temperature variables meet.

1. The ambient temp inside the ferm chamber; this drives the fermenter's chilling (or accessory heating) process.
2. The beer temp inside the fermenter, along the fermenter wall (not the center); during active fermentation the thermals take care of continuous mixing of the beer; when things slow down so does the generation of heat.

IMO, this reduces larger over- and undershoots of the beer temp due to lag (hysteresis) of heat transfer.
A thermowell in the beer can't measure 1. It only measures 2.

Now it would be nice and handy to measure/monitor the temp in the center of the fermenter with a second probe in a thermowell. But for reference only. Not for (directly and solely) controlling the ferm chamber's temp.

 

[RPh_Guy]

during active fermentation the thermals take care of continuous mixing of the beer

Right, I've tested mine with calibrated thermometers and the probe insulated against the outside reads within 0.1°F of a thermometer in the middle of an active fermentation.

FYI, a stick-on thermometer (e.g. Fermometer) also accurately measures the temperature.

I agree with @IslandLizard it's also not good for things like cold crashing, or even cooling before fermentation becomes active. Cooling will undershoot and heating will overshoot.

 

[sicktght311]

Typically my liquid is within a degree or two of the target fermentation temp before it goes in the chamber. I place the probe in the thermowell and set my desired temp. Never had a problem. 90% of the time the chamber is cooling the beer during fermentation but it’s not like the temp shoots up 5 degrees in 30 minutes and the fridge is trying to compensate. Again I’ve never had a problem lol

for cold crashing I’ll pull the probe out and place it in a small jar of water and then set my target cold crash temp

 

[RPh_Guy]

Typically my liquid is within a degree or two of the target fermentation temp before it goes in the chamber. I place the probe in the thermowell and set my desired temp. Never had a problem. 90% of the time the chamber is cooling the beer during fermentation but it’s not like the temp shoots up 5 degrees in 30 minutes and the fridge is trying to compensate. Again I’ve never had a problem lol

Sounds about right. I'm not saying that using a thermowell is harmful (during fermentation), just superfluous.

 

[day_trippr]

fwiw, over the years I've read all kinds of anecdotes claiming a strapped/insulated probe will read within a degree of a centered thermowell. But tmk nobody ever demonstrated that conclusion.

So, in the interest of SCIENCE! I'm all set up to do some temperature differential testing between a strapped probe and thermowell on the same fermentor, and also comparing a second fermentor in the same chamber. Next batch should be modestly revealing, though I expect it will conform to the CW.

Some of the probes are connected to one of my BrewPi Bluetooth minions that controls this fridge based on its strapped fermentor probe. The rest go to a spare RPi running my temperature logger/plotter. All of these probes were selected from a larger set for their correlation (+/- 0.1°F as best as I could determine through a few days of plotting) though my logger supports probe offsets if needed.

Here I'm running the system through a +5°F temperature ramp to check everything is working as expect. And it immediately revealed what everyone should expect: there's a ton of lag from strapped probe to thermowell when there's a ramp - caused by external influence - in effect, but eventually they re-converge at the end of the ramp.

What I want to know is if a ramp is caused by internal influence (ie: raging yeast) what the plots will look like.

Next batch will be spit between these two carboys...

Cheers!

 

[RPh_Guy]

But tmk nobody ever demonstrated that conclusion.

I just said I tested mine with calibrated thermometers (during an active fermentation) and the readings were the same. Did you want photos?
The turbulence from fermentation homogenizes the temperature.

And yeah, it's super easy to test yourself as you're doing.

 

[day_trippr]

I'd want to see setup and process. I've never seen that, just random "they're the same" without anything to back it up.
So...

Cheers!

 

[bkboiler]

Glad I read this...my temp probe dangles at the back of my chamber and I always just change the temp in the chamber to cooler at the beginning of fermentation and warm it up each day...
Was literally researching thermowell solutions today...

#popcorn

 

[Robert65]

Glad I read this...my temp probe dangles at the back of my chamber and I always just change the temp in the chamber to cooler at the beginning of fermentation and warm it up each day...
Was literally researching thermowell solutions today...

#popcorn

I may be an iconoclast... well, no question about that. But. I still control ambient temperature in my chamber, monitor the temperature in the ferment, and act, my human self, as the PID. I have tried various methods of getting the probe on my controller to monitor ferment temperature, and it has resulted in serious stress on the compressor and wild swings in the ferment temperature. I realize that this is the opposite of many other people's experience. The point is, lots of factors are in play, depending on your equipment, and there's no one right answer. Figure out what works for you.

 

[day_trippr]

I don't know about iconoclasts - or luddites but I definitely don't get the whole "wild swings" thing.

Before I went all-in on my BrewPi controllers I used Love TSS2 controllers (well before the uber inexpensive STC1000's showed up in the marketplace) with strapped probes (I've always used strapped probes) and they had no problems tracking my fermentors and controlling both fridges and heaters with the differentials I allowed.

BrewPi allows both tighter control (as it "learns" how the system responds) and remote control and monitoring, but at the end of the day it's not that different from an Inkbird dual-channel controller wrt keeping the fermentation in the target temperature zone. As long as the controlling sensor has both good thermal coupling to the wort and good thermal isolation from chamber temperature any decent controller should prove better than "nanny mode" control...

Cheers!

 

[TexasGuy]

Okay...so I'm bought in now that using a thermowell to control temperature is not the best way to go, but it is good for internal monitoring.

1. How are you applying your probe to the carboy?
   My carboy is wrapped up in a carboy cover (this one...fits perfectly by the way, I highly recommend) with a heater wrap around 3/4 of the carboy inside the cover.
   
   
2. What about probe placement in a Kegorator?
   My kegorator has a cooling shield along the back wall and some of the side walls. I got a little better results when I put a couple computer fans in it, but not sure if I should tape the probe to the bottom of the space, between the kegs and shield, between the kegs and door, or to an active keg side not facing the cooling shield. I replaced the original thermostat 5 years ago with an STC1000 (works really well). Measuring temps definitely did not work accurately hanging the probe near the top of the kegorator above the cooling shield, but did work better by insulating the probe with a piece of cardboard between the keg and door halfway up. I had to set the thermostat to freezing to get the kegs to pour 37 degrees.

 

[RPh_Guy]

(2.5 gal of kviek fermenting at 92°F held with FermWrap)

• Tape the probe to the side.
• Tape a piece of insulation over it.

Use easy-to-remove tape like packing tape or painters tape.
You may be able to forgo the insulation since you are using a cover. Or some thin insulation might help (e.g. a sponge, a folded sock, or some reflectix). I don't see the point of the cover.

Can't help with the kegerator question.