Anybody using a Coleman Extreme 100 qt as a mash tun? If so what are your thoughts on it’s performance? Coleman also has a 100 qt Marine cooler that has a anti microbial additive in the interior plastic, which sounds like something I don’t want in my beer! I have been using a 50 qt cooler with good results so far, but I want to up my batch size.
How big are you thinking of going? I have a 70qt extreme and can fit about 32lbs. Do you need more than that?
I have done several “no sparge” batches where I add all the water (mash and sparge) at once. The beers I have made this way turned out great, they have great head retention and a very smooth malt character. I need more volume to do 10 gallon batches this way.
I’m sure it will work fine. I’ve got a buddy with the 120 that he uses for 15 gallon batches and it works as well as my 70. I also have a 50. I use whatever is appropriate for the volume.
I got a 70 qt when they went on special @ Amazon for something like $39. It’s all I ever need (and more than I usually need).
Amazon Prime is the Best price I found. I ordered a 100 Quart, Now the problem is where to store it, it’s almost the size of a small bath tub. 
What mash ratio are you using for that?
1.7 with room to stir. Can for sure go bigger with a thicker mash. Can I mash it says I could do 50lb at 1qt/lb
I wouldn’t worry over much about the anti microbial additive. Several years ago we started seeing refrigerators that advertised the anti-microbial plastic, as I recall it essentially is a formulation that produces a surface that bacteria and other microbes are unable to survive on. It doesn’t “poison” them, it simply isn’t a surface they can live on. Probably an over simplification.
Good to know. Now I wish I ordered the marine version of the chest, it was cheaper and the handles looked sturdier.