does a cooler mashtun hold temp in winter?

[drfritz]

im thinking about converting a cooler to a mash tun so i can brew in the garage instead of the kitchen. I live in the northeast and during the winter i am concerned that the cooler wont hold the temp for the mash. anybody have any experience with this?

 

[Bobby_M]

If you take my advice and preheat with HOT strike water, tilting the cooler to coat the walls, you shouldn't lose more than 2F over an hour.

 

[mattmcl]

I just move my cooler indoors for the mash. The tall round beverage coolers are pretty easy to move, even when full. You can also put a sleeping bag over the cooler. I don't lose more than 1F over an hour with either method.

 

[SamuraiSquirrel]

Just brewed a batch this weekend here in Chicago. I think it was in the teens or twenties outside. I use a ten gallon round igloo cooler. Started at 154 and ended at 152 after an hour mash. Opened once during the mash to stir for a minute.

 

[bob1852]

If you take my advice and preheat with HOT strike water, tilting the cooler to coat the walls, you shouldn't lose more than 2F over an hour.

This is true...

I did this three times over the weekend (air temps during the mash were in the low 30s)...pre-heated, and didn't lose more than 1F.

It helps to bring your MLT in at night also, so you're not trying to pre-heat a cooler that's been sitting in 20 degree weather all night.

 

[BendBrewer]

If you take my advice and preheat with HOT strike water, tilting the cooler to coat the walls, you shouldn't lose more than 2F over an hour.

And you'll discover surprise leaks in advance as well.

 

[joeunc]

must preheat, I did one yesterday and it was about 36 out. I put 185' water in my coleman extreme and really only let it sit 2mins. I didn't swirl it around or anything. When I put 12.5lbs grain in, ,my temp crashed below 155 and I had to play catch up for the whole hour it seemed. I moved the cooler inside and every 15mins added some hot hot water and stirred to make sure I stayed over 150. What I learned about mashing in cold would be,,make sure preheat thoroughly, and bring the MLT indoors the night before. Sitting out in the garage overnight and then and early morning brew can just leech the heat out.

 

[Homercidal]

I've always preheated my tun and never had a problem. But I've lost more than 2 degrees once. The lid is not insulated and it was colder than 20 F. I would probably think about covering it with a blanket to help hold the heat in in that case. But lately I've been mashing in the house and boiling outside.

 

[DirtyPolock]

I'll agree with everybody here and summarize.

1) Bring in your MashTun overnight so it is not very cold to begin with.
2) Pre heat your cooler (I found that I need a preheat of about 10 degrees higher than stike temp)
3) Either keep the mash indoors, or wrap a blanket around to add some extra insulation

By doing these you should be pretty good and barely lose any temp during the mash

 

[weirdboy]

I always carry a couple of old towels & blankets out with me when I'm setting mine up, and throw them on top of the cooler when I am preheating and mash in. Then I reuse the old towels and throw them onto the kitchen floor so that if I need to step back into the kitchen with dirty shoes, I don't make a huge mess.

 

[Misplaced_Canuck]

If you are in moderate to severe cold weather (under 10F), I'd recommend heating up a blanket or a sleeping bag in the dryer for 15 minutes and wrapping it around the mashtun.

M-C

 

[drfritz]

thanks to everyone that replied, great info. im waiting for delivery of my rubbermaid 10 gal cooler and converted keg brew kettle. i will try a mash as soon as i get it set up. hopefully it will be a little warmer than the teens and twenties we've been having lately

 

[steinsato]

I just move my cooler indoors for the mash. The tall round beverage coolers are pretty easy to move, even when full. You can also put a sleeping bag over the cooler. I don't lose more than 1F over an hour with either method.

Same here, I usually brew on my back porch but when it's cold out, I simply carry it inside and forget about it.

 

[sbushwhacker]

I just did a brew on MLK day, 10 degrees outside. I kept my mash tun cooler in the basement. Heated strike water in the garage then transferred to tun in the basement with no problems. The problem I had was doing an open boil in the garage at 10 degrees and low humidity left me short on wort! Heavy boil out. Steve

 

[drfritz]

thanks, i think i will do everything except the boil inside until spring, just seems easier

 

[shortyjacobs]

I brew in my garage, and live in Minnesota.

I have a 15 gal ice-cube cooler.

Tips:
Fill the lid with greatstuff foam, (get the Windows and Doors stuff, it's got lower expansion, won't warp the lid).

My garage usually heats up to low 50s or 60s with a few minutes of turkey fryer heat for heating mash/sparge water.

Preheat the tun. I put in water 10 degrees higher than strike temp, and wait for it to come down.

I lose only a degree or two, no big deal, works great.