Temp sensor on a thermopot ?

[fordpopular]

I would like to add a temp probe to my mash tun (thermopot) and rather than make a hole through both skins and adding a thermowell or stainless probe I was thinking of cutting through the outer skin and adding a standard STC1000 probe pressed up against the inner skin.. has anyone tried this, any advice would be appreciated

[Andy]

If I were going to the level of drilling holes then I'd go the whole hog and install a probe inside the tun rather than what you're describing.

[Hogarth]

Even in a thermopot, the temperature of the mash drops off significantly at the very edges -- often by several degrees -- and that's what you'd be measuring with this set-up. A probe in the centre of the mash would give you a higher reading. Neither of these can really be said to the 'correct' one, though. This is why I've never bothered fitting a probe in my mash tun at all. I prefer to poke around with a digital thermometer and come up with an average reading. (Which means, in practice, that I poke around until I find a spot that's exactly at the target temperature, and say 'spot on!')

[orlando]

What will you do with the information? If you want to keep the mash temp stable throughout the mash time RIMS or HERMS is the answer and you wouldn't have to drill the pot unless you don't have a return valve.

[ciderhead]

I drilled and put in a 3" Dial in my MT with a 6 inch probe, as Orlando says complete waste of time and I regret doing it, far better measuring temp in and out on a Herms/Rims if you are intending doing that longer term.

Edit I forgot to mention its 3-4 degrees lower in temp than my thermopen in the middle of the mash which would confirm comments about thermal conductivity, what was I thinking!, don't do it!!

[Kev888]

The thermowells can at least give a guide, once you know the typical temperature gradients of your mash tun (though IMO they get in the way of stirring etc. so I also prefer a hand held probe that can be prodded around when needed).

However the very edge, in fact outside the very edge, of the mash is perhaps the least representative place to take a measurement; the mash is a reasonably good insulator (compared to water) and stainless also a reasonably poor conductor (for a metal) and then there is the probe/metal contact resistance. It would depend on how effective the insulation was, but the temperature change between probe and mash could be quite high. So it could give you some kind of relative indication brew-to-brew but I'd hesitate to use it as an accurate direct measure of mash temperature,

[Fil]

had similar thoughts myself, when considering temp control options on a thermopot fermentor, I ended up going thru the lid with a hex coil and deep thermopocket, I would go in under the base and attach a surface mountable sensor against the thin inner skin before covering back up with some insulation.

for pt100 probes of all sorts (damn lost the link...) Barneey found a great value German supplier of all types of probes sorry ive mislaid the link..