Originally Posted by opiate82
So I had a big styrofoam box out in the garage. I cut a circle out of it big enough to fit snuggly inside my 10gal Home Depot Cooler Mash tun then wrapped it up in a food-safe bag and zip-tied it shut. The circle is probably about 2" thick and it is your typical white styrofoam used for packing or as disposable coolers. Brewed a Blonde with just 9lbs of grain. Grain + Water took up less than 1/2 of the space in the tun. I had recently discovered I was losing a lot of heat on small beers like that (9 degrees on my last one). With my styrofoam circle resting just above the grain bed I lost less than 1 degree. Nothing changed in my pre-heating or dough-in methods, everything was exactly the same other than the, I guess you would call it a false-top.
That's what I do. I got a few sheets of styrofoam from lowes and cut to fit inside my round cooler, And it rests right on top of the mash.
Drinking Pumpkin ale V2, Oaked Wee heavy, The Kaiser clone, Graff, Old Jubilation clone, Sour Cranberry Ale
Carbing/Aging Westy 12, Barleywine
In the bucket Peach Wit (FINALLY!)
On Deck Westy 12 (19X), Pumpkin Ale 2014, FBS clone, Port oaked amber, Old Rasputin Clone, 15% RIS