I’m always worried about checking mash temp in my cooler mash tun for fear of losing heat so I came up with a low tech solution. A small 2-4 ounces plastic cup that I use as a ‘boat’ for my waterproof lollipop thermometer. With this I only have to crack the lid a little to check the temp. I can hold my temps to within a degree for 60-80 minutes. Gotta love the cheap solution.
Totally cool. They need to make a rubber ducky mash thermometer
Use a little larger plastic container…one with a see thru top. The hot steamy closed up mash tun will do in your thermometer fairly quickly. Protect from condensation and the set up works fine.
My first mash tun was the same kind of cooler you have. I had an analogue thermometer with a 12" spike. I drilled a hole in the lid just large enough to insert the spike into the mash. Worked great.
Paul
It’s supposed to be water proof but I think you’re right. Condensation inside the LCD will kill it eventually. The lid’s a good idea!
Why do you need to check temp so often that you lose heat? I check it at the beginning of the mash and maybe once during the course of the mash. Why not get your temp, close up the cooler and leave it alone?
+1
+2. I stopped checking mid-mash a long time ago. I get a good consistent temp throughout the tun, close it up, cover the cooler with a thick blanket and leave it alone.
1. Peeking is more fun
2. Triple decoction mashes
3. Inquiring minds want to know
4. Because we can
In the cold weather you can lose a fair amount of heat, even in a blue cooler. I generally check 5 minutes in, 15-20 min then at the end of the mash. My Thermometer takes about 8-10 secs to register and stabilize. Putting it in the clear container probably saves an aggregate minute of having the lid open. May or may not make a big difference, but it costs nothing to do it and saves having to hold the lid open.
I use a dial thermometer and just leave it in the mash tun. In the rare situation I need to know the temp during the mash, I can just open the cooler a bit and peek at it. I’ve used the same thermometer for 16 years so it must not be harming the thermometer.
It must be a lot colder where you are than where I am. A cooler in my garage never loses more than 2-3 F over the course of a mash, even with ambient temps in the 20s.
Yup, a good ol’ dial thermometer will last a long time. The OP and I are using digital ones though, and you really can’t leave them in the mash unless you protect them. The plastic container was just a cheap and easy solution. You are right, I usually only lose 3-4 degrees over the course of a mash when it’s really cold, but I’m assuming if I can reduce the amount of time the lid is open it’s a good thing.
I kind of obsess about trying to make a nice full bodied beer and finding at the end of the mash I’m below
the temp I wanted to be. Over attenuation is a pretty consistent issue for me. I select my yeast strains carefully and do pretty careful control on pitch rates. What’s left to monitor but mash temps?
I look at it like baking a cake or cookies. Don’t open the oven (mashtun).
Get your temp right at the start and trust it will stay the same. The more you open it, the more it is going to lose heat. I lose about 1° during the summer and 2-3° when the temps are low.
The more airspace you have the worse the drop will be. In the case of the OP, there is very little airspace, so it won’t be too bad.
I just moved from BIAB to a cooler mash tun so I guess I’m at the stage where I’m learning my new equipment. Having said that, my first batch lost about 1 degree over an 80 minute mash. I checked it once at 10 minutes in and again at 60 minutes mostly to see how temps we’re holding. I can see now that It’s a lot more steady than my BIAB ever was 
It must be a lot colder where you are than where I am. A cooler in my garage never loses more than 2-3 F over the course of a mash, even with ambient temps in the 20s.
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Denny…So do you even bother to compensate for the 2-3 degree of temperature loss? If you hit your mash temp of say 152 and after an hour you are down to 149-150 do you just roll with it? Of course we all know it will make beer but I have always wondered how important it is to maintain the exact temperature for the full 60 min duration.
Nope, I don’t worry about it a bit. Close enough. If I start at 152 and after an hour it’s 150, it won’t make enough difference to notice.
First off, very nice thermometer. I have the same one and would recommend it to anybody. Long stem and cheap. But it concerns me that you are losing enough heat to be focused on checking the temp. I mashed in two weeks ago and it was 4 degrees out. I lost 1 degree in 60 minutes. I mashed I. Yesterday at 37 degrees out and lost .4 degrees in 90 minutes. It must be because mine is blue ;D
Just my two cents, when I started out, ( many moons ago) I too was worriedabout mash temps, and like most I was using a good old rubber tun. My solution was simple. Drilled a hole in the lid, stuffed the lid with foam, inserted my thermometer, sealed it up with fda approved silicon. Never worried about it again.