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 Fat Tire Clone
Carbing/Aging Westy 12(new world), Chocolate stout V2, Pumpkin Ale V2.5 (1st batch 2014)
In the bucket Pumpkin Ale V2.5 (2nd batch 2014), Kinda Double Bastard
On Deck The Kaiser, Blue Moon, oatmeal porter