Keeping Mash temp during 90min Mash in 5gal Cooler MLT

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KYB

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So I need to do about a 90 minute mash and was wondering how I could kept the temp close the whole time. Is there any good way to heat a cooler MLT without adding more water (and not melting it)? Of course keeping the lid screwed on the whole time, but I imagine it will cool a fair amount after awhile. I have 13.75 lbs of grain, and plan to do 1.1 qt/lbs, so it's going to be a tight fit.

Also, do I stir it during the mash or just leave it be? I'm going to fly sparge, I know I don't stir it during sparging.

Thanks for any help.
 
Iues a round 10 gallon tun. To heat it, just heat it about 3-4 degrees above your strike temp. (if your mash tun is real cold, maybe a degress or two more)...Then pour your mash water i the tun and it will absorbe the excess heat. I always go a little higher, so that you can always stir the water to get it down to strike temp. Then pour in you gain, stir and let be....

As far as maintaining temp., I cut a piece of styrofoam to fit inside the mash tun...Covered it with duct tape, and poked a hole it it for my thermometer probe. Iplace this on top of the grain bed during the mash....I'm able to keep the temp within a degree for a 90 minute mash....The foam I used was fairly thick. It was from the cooler you get when you order Omaha steaks....It almost 2"....And I actually made 2 foam covers, just because I had extra and I coudn't hurt.

hope this helps...

Oh and stir after the first 10 minutes, then every 1/2 hour or so...
 
wild duk makes two awesome points- in these winter months, I ALWAYS have to heat my cooler up- and like to do so by adding a few gal. of Near boiling water, and swirling it all around....(Then it will be cleaning water later). I think their styrofoam idea rocks! I know that Boiling water is going to Warp your cooler before it Melts it......
Also, maybe you have already considered this, but you could shoot for the higher end of your target range in order to keep the targeted enzymes active for the 90 min duration even if it looses some heat....Say like from 158 down to 152, etc.
And I personally do typically stir it up every so often-
 
Awesome. Yea I was planning on preheating it with water, but figured the temp would still go down a fair amount. I might try that Styrofoam idea and I'll definitely have a slightly higher temp to start out with. Thanks a lot!
 
I have a fairly thick walled cooler. I preheated yesterday with 180 degree water and mashed outside with the temperature in the low 40's. Minimal if any heat loss.
 
I have a fairly thick walled cooler. I preheated yesterday with 180 degree water and mashed outside with the temperature in the low 40's. Minimal if any heat loss.

:off: what brand is it? I'm looking to go square, and have been window-shopping for ages pondering which ones might loose heat, etc. Is it square? Thanks'
 
I just use the orange round rubbermaids from Home Depot. With the tecnique described above, I can mash for 90 minutes and loose maybe 1 degree, even when its 30 out....
 
You shouldn't lose more than 1F with a full tun as long as you get it up to temp. Put your strike water in at about 180F and let the cooler suck the heat in before you stir in the grain.
 
Good to know, thanks. You all stir it a few times and only lose about 1*?
 
:off: what brand is it? I'm looking to go square, and have been window-shopping for ages pondering which ones might loose heat, etc. Is it square? Thanks'

Mine is more of a tall rectangle. It's a Coleman, but not sure what model. If you are looking for the best cooler out there for holding temps, most people will recommend one of the Coleman Extreme coolers. They come in a few different sizes.
 
when i do smaller beers in a 10 gallon round Igloo cooler I use a piece Styrofoam cut to size and just let it float on the water. I covered it with aluminum foil so as not to get any little pellets in the strike water. I just do this because there is so much head space doing smaller grain bills. Lose maybe 1° an hour at most
 
I was skeptical about the styrofoam floating in hot liquid, but aluminum foil wrapping sounds like it would be safe.
 

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