Styrofoam mash tun lid?

[born3z]

I'm currently mashing in a rectangular cooler that loses about five degrees over an hour long mash. I know most of the heat is coming out the top. Is there any reason why I cant make a lid out of Styrofoam so long as it doesn't come in contact with the mash?

 

[Bmorebrew]

Just wrap it in aluminum foil.

 

[JonM]

That's exactly what I do, and it works like a champ.

Just don't store the new lid in the cooler after use - you'll get mold.

 

[tre9er]

You could put the styrofoam on the outside too and wrap the whole thing in a big-ass blanket. I use a rectangular 22qt. cooler and finished at 152 after an hour (which is what I was shooting to mash at, so I think I started at 154)

 

[born3z]

I'd rather not wrap it in a blanket. Although that does work really well. Looks like I'm making a styrofoam lid. Thanks, fellas.

 

[rockfish42]

I'd drill a small hole in the existing lid and fill it with spray insulation.

 

[day_trippr]

I'd drill a small hole in the existing lid and fill it with spray insulation.

Sounds good, but people that have tried that found the foam never cures...

Cheers!

 

[born3z]

It's a two pieced lid that doesn't seem to seal very well. I can see steam coming out of the cracks when I pour in my strike water.

 

[Komodo]

Sounds good, but people that have tried that found the foam never cures...

Cheers!

Yeah, this was me. Cut your styrofoam or blueboard insulation to just slip fit inside the cooler. Wrap in aluminum foil/aluminum tape, don't forget to mak a couple tabs to be able to grab it and pull it out. When you mash, slip it down inside so it just rests on the top of the mash, then cover with the regular lid. You'll probably lose 1 degree in an hour at the worst if you use 2" foam.

Here:

 

[DSmith]

I tried the spray foam before cutting a 2" piece of pink styrofoam. The spray foam was a mess, probably overfilled it and didn't dry properly with air voids. My testing with hot water in the cooler showed it made no difference.

The insulation lid (wrapped in a food grade bag - my mash tun is round and the lid fits in a turkey bag) made a huge difference with holding the temperature of hot water for testing. An actual mash can easily be held to a degree with a little mixing at 5-10 minutes into the mash to even out thermal gradients.

Wrapping it well in aluminum foil or wide plastic wrap sounds like a great idea.

Wrapping the mash tun in a blanket also is a good idea because it's so easy.

 

[JonM]

^ This. Exactly.