Adding a thermometer to a mash tun

Hey guys,

I see that some people on here have a thermometer through the wall of the mash tun cooler. How are you guys doing this? Is a fitting or something as simple as a hole smaller than the thermometer? Any bulkhead fitting won't go through the thick (1.5") wall of the cooler. I have a 10g Rubbermaid cylindrical cooler.

Currently I'm checking the temp by taking the top off and checking a few spots in the mash, but I'd rather avoid having to take the top off at all if I can help it.

Thanks all!
paul

I HATE my through-wall thermometer. Since the probe barely sticks out past the wall of the cooler, it's very inaccurate and usually measures quite low. I wish I'd never installed it.

If you're doing a single infusion, hit the strike temp, dough in, close the lid, and forget about it. No need to constantly monitor the temp.

Thanks for the feedback Yuri. I'm not "constantly" monitoring, but I do check after 30 min and then if I mash out I'm checking. I may go with a digital thermometer with a probe then.

Instant read thermometers are the way to go, but buy a good one. The cheap ones aren't worth the frustration.. they break, they get out of whack, etc. Also keep in mind the probe type thermometers with a cord are not good for mashing. If the probe gets wet, it will be ruined. I destroyed two of them before I figured out they aren't waterproof.

Also keep in mind the probe type thermometers with a cord are not good for mashing. If the probe gets wet, it will be ruined. I destroyed two of them before I figured out they aren't waterproof.

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Ahh, but they can be easily made waterproof with a bit of aquarium tubing.

I've been using mine for the past 10 batches and it works like a charm.

flyangler18 said:

Ahh, but they can be easily made waterproof with a bit of aquarium tubing.

I've been using mine for the past 10 batches and it works like a charm.

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OK so what did you do and where'd you buy it? I haven't seen a thread on waterproofing those.. Sounds handy!

Well, I usually defer to either Yuri or Bobby_M on all things brewery DIY, and this is no exception!

https://www.homebrewtalk.com/f11/remote-probe-thermometer-wort-proofing-26905/

Go to your local pet retailer and get the small silicone aquarium tubing- not sure what the ID is, but it fits the probe like a glove along with a couple #70 o-rings.

That is sooo cool. And seems so much better than drilling through my precious Coleman Xtreme 70.

Nice! I think I found my solution! thanks for the help guys

Saccharomyces said:

Instant read thermometers are the way to go, but buy a good one. The cheap ones aren't worth the frustration.. they break, they get out of whack, etc. Also keep in mind the probe type thermometers with a cord are not good for mashing. If the probe gets wet, it will be ruined. I destroyed two of them before I figured out they aren't waterproof.

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Ditto. I went throught 2.5 (i still use the body of one as a timer!). I returned one of them, smuggly asking the clerk if it felt like 440F in the store. Which it did not.

I had no idea those were not waterproof. Seems kind of odd. Anyway, I'm glad I read this.

Saccharomyces said:

Instant read thermometers are the way to go, but buy a good one. The cheap ones aren't worth the frustration.. they break, they get out of whack, etc. Also keep in mind the probe type thermometers with a cord are not good for mashing. If the probe gets wet, it will be ruined. I destroyed two of them before I figured out they aren't waterproof.

Click to expand...

I think that explains what happened to my old barbecue probe thermometer... Suddenly it said it was like 150 degrees in the room.

I just use a 3/4 rubber stopper
-drill a hole through it to insert my thermometer .
-drill a hole in my cooler slightly smaller then the stopper and wedge it in

I measure the mash temperature and once it is at target I close the top. In the winter I wrap it up with blankets. I lose less than 2 degrees in the hour. I use a Thermapen and measure in several places. It takes only seconds to stabilize. Cheap thermometers take too long.

Yuri_Rage said:

I HATE my through-wall thermometer. Since the probe barely sticks out past the wall of the cooler, it's very inaccurate and usually measures quite low. I wish I'd never installed it.

If you're doing a single infusion, hit the strike temp, dough in, close the lid, and forget about it. No need to constantly monitor the temp.

Click to expand...

I agree with Yuri_Rage. Unless,.... you are able to recirculate your mash and have an inline heat exchanger you can ramp on and off when temp falls or keep constant throughout the mash. I use a long probe on my thermometer and the recirculating mash eliminates temp stratification in the tun.

If not recirculating, do your best to hit mash temp, close the lid and let it ride.

fwiw, I use one of these through a 1/4" hole in the dead center of my 10g Rubbermade MLT lid.

I slipped a grommet on it so I can set its height relative to the middle of the grain bed when not actively checking temps.
And because the center of the cooler lid is a very thin cross-section (no insulation there) I can manipulate the thermometer to reach all around the bed to check for hot/cold spots after dough-in with the lid on before giving the whole thing a good leaving alone...

Cheers!

[edit] Yikes! That thing has gotten expensive - I paid $24.90 for mine, delivered!
Wait for a sale

The issue with a thermometer in a mash tun is the temps will usually vary at different areas of the mash tun unless you recirculate... and if you do that putting the thermometer in a tee at the exit point before the pump works well. otherwise just sticking the probe in from the top at different area to get an average is what I would do.