Thermometer for an orange Igloo mash tun

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Mcbobs

Well-Known Member
Joined
Sep 26, 2009
Messages
264
Reaction score
45
Location
Manhattan
Hey guys. I'm slowly rebuilding my all grain brewery and am utilizing the orange rubbermaid round style cooler for my mash tun. I'd really like to be able to put a permanent thermometer on it to keep an eye on my mash temperatures, but can't figure out what style of thermometer I should use.

I just purchased two weldless Blichmann thermometers for my HLT and boil kettle. I really like these thermometers, but can't figure out how I would use one on my mash tun.

What does everyone else use? Is there a way to get the Blichmann thermometers to work on my mash tun?

Any great ideas? I'm pretty stumped at the moment....
 
I am sort of in the same boat. I chose a weldless thermometer with a 6 inch probe and a 3 inch dial. I am thinking of installing it as low as possible to the false bottom so that it minimizes the risk of being hit from stirring. Does anyone have any suggestions on this? Thanks.
 
I was thinking about mounting one tthrough the center of the lid. That way it wouldn't be in the way when stirring. I spent a little time looking for one with the length I wanted but didn't find one.
 
Uh, drill a hole in the side and install it?

Seriously though, take a look at the manual for the Blichmann Autosparge. On page 2 they show how to install it in a cooler MLT, the principle is pretty much the same for your Brewmometer.
 
So I didn't want to drill a hole in my tun and worry about sealing it and all the jazz.

My remedy was a cheap analog thermometer and the cap from one of the new Tropicana OJ bottles.

I drilled a hole in the cap and pushed the thermometer through. Then I just set it in my mash once everything is stirred up and good and leave it in the tun the whole time. It fogs up a little but it floats and it lets me know instantly if I lose any temperature.

When I mash-in I have a $20 digital thermometer that is waterproof that I dip in and swish around to make sure I hit my mash temperature. Then I drop the analog in the tun with the OJ cap-floatie and close the lid. I check it every 20 minutes or so to make sure its good.

Simple fix, $30 tops. If I ever win the lottery I may but a Thermapen but that overpriced accuracy can wait. For all my homebrew purposes, my set up works just dandy.
 
Last edited by a moderator:
I was reluctant to drill a hole in the side too, so I drilled a hole in the lid sized for a stopper and used a thermo well: http://www.brewershardware.com/16-Stainless-Steel-Thermowell.html
Now I can slide the probe from my digital thermometer down the thermowell or remove the thermowell easily if necessary. I use the same thermowell for my fermentor by simply drilling the appropriate hole in the lib (it's a plastic bucket fermentor)
 
I wouldnt worry about the temp of the mash inside anyways.

Even with an ambient air temp of around 60, I lose maybe a degree or two with my 10 gallon cooler MLT, even with a decent amount of head space(if I am mashing thick or something).

Any attempts to monitor the temp without stirring will be futile anyways because of the hot and cold spots that develop.

Get your mash temp where you want it, shut the lid, and forget about it.

If you are so inclined, measure the temp at the end of the mash just to see how much you lost. I'll bet you 10 bucks you dont do it more than a couple times.
 
i like the thermowell idea through the top and have made one out of copper but found it not very accurate. i was told to use thermogel but i can imagine that to get messy. any thoughts on this or is the stainless one accurate without the gel.
 
I also was wondering if I needing some sort of heat transfer fluid in the thermowell. I put my probe in boiling water 1st by itself and then again inside the thermowell and I didn't see a difference. In my case, I mainly got the thermowell for the fermenter, but it's also nice to know what the mash temp is doing.
 
It's just pink styrofoam board from Home Depot. Cut to fit and wrapped with aluminum foil so the styrofoam doesn't get into the mash
 
I know people have been drinking from styrofoam cups for ages and the jury is out on the health issues for that but I just have a sense that polystyrene mashing with my beer may have some carcinogenic properties. I don't think I will try that.
 
Here's what I did:
I used a square coleman cooler but the principle will work on any cooler with a 1/2" female npt ball valve. Where the ball valve attaches to the nipple going through the cooler wall, remove the ball valve. Install a 1/2" female tee in its place with one tee opening heading directly into the cooler and the other branch of the tee perpendicular to the hole in the cooler, but in the same plane as your manifold. Install a thermometer with a 3 to 6 inch probe and a male 1/2" npt thread into the branch of the tee that is inline with the nipple so that the probe sticks into your manifold on the inside of your cooler. Attach your ball valve to the other branch of the tee using a 1/2 by 1 inch nipple. I haven't yet mashed with this set up because I just finished it but I have filled the cooler with 160 deg water and drained it and it doesn't leak, the temperature is dead accurate with 2 other thermometers, and the water drained as fast as it should.
 
I wouldnt worry about the temp of the mash inside anyways.

Even with an ambient air temp of around 60, I lose maybe a degree or two with my 10 gallon cooler MLT, even with a decent amount of head space(if I am mashing thick or something).

Any attempts to monitor the temp without stirring will be futile anyways because of the hot and cold spots that develop.

Get your mash temp where you want it, shut the lid, and forget about it.

If you are so inclined, measure the temp at the end of the mash just to see how much you lost. I'll bet you 10 bucks you dont do it more than a couple times.

My experience says the same. There's really no need to monitor the mash temperatures once the lid is closed.
 
Here's what I did:
I used a square coleman cooler but the principle will work on any cooler with a 1/2" female npt ball valve. Where the ball valve attaches to the nipple going through the cooler wall, remove the ball valve. Install a 1/2" female tee in its place with one tee opening heading directly into the cooler and the other branch of the tee perpendicular to the hole in the cooler, but in the same plane as your manifold. Install a thermometer with a 3 to 6 inch probe and a male 1/2" npt thread into the branch of the tee that is inline with the nipple so that the probe sticks into your manifold on the inside of your cooler. Attach your ball valve to the other branch of the tee using a 1/2 by 1 inch nipple. I haven't yet mashed with this set up because I just finished it but I have filled the cooler with 160 deg water and drained it and it doesn't leak, the temperature is dead accurate with 2 other thermometers, and the water drained as fast as it should.

So wait - if I'm picturing this right, the valve is basically parallel to the cooler, instead of perpendicular to it, as is typical for most installations?

The only hangup could be for folks using manifolds or false bottoms - the thermometer probe would necessarily have to be inside the tubing connecting that manifold or false bottom to the bulkhead - so if your probe is too long, you're kind of hosed. And if your probe isn't long enough, you're not necessarily measuring the temperature of the grain bed itself.
 
So wait - if I'm picturing this right, the valve is basically parallel to the cooler, instead of perpendicular to it, as is typical for most installations?

The only hangup could be for folks using manifolds or false bottoms - the thermometer probe would necessarily have to be inside the tubing connecting that manifold or false bottom to the bulkhead - so if your probe is too long, you're kind of hosed. And if your probe isn't long enough, you're not necessarily measuring the temperature of the grain bed itself.

Ya, that is correct, the valve is perpendicular to the cooler. I have a 3/8" pvc manifold and it works ok. I had to play with the stack up between the washers, orings, nuts, and nipple to make it work, and I had to use a 3/4" pvc coupler inside of my cooler as a spacing sleeve between the bulkhead washer and where my manifold connects because I had to use a 3.5" nipple to accomodate my thermometer with a 5" long probe..... it did take some experimentation and I had to return about $20 worth of fittings to home depot after I found out what I needed to make it work. I was concerned about the temp difference between the water sitting inside my manifold at the bottom of the cooler and the water near the lid of the cooler, but after I let 8 gallons of 160 deg water sit in the 10 gallon cooler for about 10 minutes, the blichmann thermo in the manifold was 1 degree lower than an instant read thermo I put in the water inside the cooler......good enough for me. After sunday I'll know if it still reads accurately with 12 lbs of grain inside, but I think it'll be close.
 
Yeah, I wouldn't be so concerned about stratification of temperature of just a pure liquid in the tun... I'll be interested to hear your observations on how the readings of the thermometer probe inside the manifold compare to the readings of a thermometer measuring the rest of the grainbed though. If they're reasonably close or, even better, spot on, then it would seem you've got a winner on your hands.
 
Yeah, I wouldn't be so concerned about stratification of temperature of just a pure liquid in the tun... I'll be interested to hear your observations on how the readings of the thermometer probe inside the manifold compare to the readings of a thermometer measuring the rest of the grainbed though. If they're reasonably close or, even better, spot on, then it would seem you've got a winner on your hands.

Well, I finally brewed this weekend and it turns out my thermometer design isn't all that great. When I doughed in, the temp on my mounted thermometer and my digital thermometer were exactly the same. As the mash went on, the temp on the mounted dial thermo slowly dropped about 20 degrees while the other held steady. When I started my runnings, the dial thermo immediately jumped back up to the temp of my grain bed. I think that since the nipple is so long plus the tee, that is a lot of metal surface area outside of the cooler and its dissipating the heat from the wort sitting on the thermo probe. All I had to do at any time to get a correct reading on my dial was crack the valve for just a second and it would read correctly for about 10 min then start to drop again. I think I'm going to drop the tee, put the ball valve in line and drill a hole for the thermometer at the level of the grain bed.
 
...

Get your mash temp where you want it, shut the lid, and forget about it.

If you are so inclined, measure the temp at the end of the mash just to see how much you lost. I'll bet you 10 bucks you dont do it more than a couple times.

This^^^

I have a 10 gallon HD round cooler. My last brew: temperature at mash in, 152. After 60 minute mash, 151.9.
 
I use a analog dial thermometer 12" probe. Drilled a hole dead center in the lid. Works like a charm
 
Back
Top