I’ve been mashing in my ten gallon brewpot for a while and am tired of fighting the temp drop even with wrapping it in a sleeping bag so I’m going to convert a cooler. I’ve read the coleman xtreme is a good one any suggestions would help. My main question is what size. Right now I mash anywhere between 8-20 lbs of grain for five gallon batches and I have to add malt extract for my Dopplebocks,Wee Heavy and Barleywines and do a very thick mash at twenty pounds of grain. Is it possible to have too shallow a grain bed and can I get a cooler that will mash 8-25 lbs of grain or would I need two sizes?
The “Can I mash it?” calculator here http://www.rackers.org/calcs.shtml will tell you how big a cooler you need. For your max 20 pounds even at 1.5 qt/lb, it says you’d need a 9.1 gallon cooler. Drop your water/grain ratio slightly and that’d fit in the 9 gallon Xtreme (which is what I use). If you want to be able to do 10-gallon batches down the road then a bigger Xtreme would be needed. Lots of folks on here use the 70-qt.
As for the grain bed being too shallow on smaller gravity batches, as long as you’re batch sparging in an Xtreme, there shouldn’t be any problem. Especially if you use a hose braid. The Xtreme has that nice drain channel into which your hose braid can fit therefore keeping the braid effectively below the “bottom” of the mash. Even the shallowest mash should work fine with that.
I still fly sparge but that shouldn’t be a problem
I have the 70 qt Xtreme cooler and just mashed a brown ale yesterday at 154 F. It did drop to 153 F…at minute 59 into the mash.
I get similar performance, even with ambient temps down to 30*F…
70 qt X-Treme here too. No complaints what so ever! Cheers!!!
So folks feel the 70 qt extreme would be ok for 5 gallon batches using 10 to 15 pounds of grain and batch sparging? I can pick up a 70 qt extreme for $40 on amazon vs $55 for a 52 qt.
I did a 5 gallon mild in my 70qt mash tun and it worked fine. I thought I forgot something because the bed was so shallow.
Does anyone fly sparge in one?
What is this you speak of, “fly sparge”? 
Aren’t flies in your sparge generally undesirable? ;D
I have a 70 qt coleman extreme and I fly sparge . . . but not in the cooler ;D I use a converted keg for my mash/lauter tun, the cooler is a cooler :o
I don’t think you’ll want to fly sparge with that thin of a bed, but you could give it a try. But really, why? The easiest way to use that setup is batch sparge, and it works great from what everyone says. Why add the complications of fly sparging? My setup has a sparge arm so it’s no big deal, but if I was starting from scratch I sure wouldn’t bother making one.
I still like to fly sparge i use the time to clean and prep equipment and maybe read a little of the paper while i’m sparging. Actually i’m usually savoring a previously brewed beer while watching the sparge. On anotehr note i saw a 72 qt coleman extreme which looks more of a square shape I might look into. I also have a sparge arm I use now with my current setup
Well, it’s pre-boil, so no worries…unless it’s a pop fly, then you’ll get a big splash, and may get scalded. ???