i have a quick question about mash tons. right now i extract brew but is ready to move to all grain brewing. i was going to make a mash ton from a large igloo cooler but not sure which is better for get the most goodies out of the grains. is the round taller coolers better or is the large rectangle coolers with the large tops better? i've heard both sides so i thought i would ask some experienced beer brewers. thanks!
Not a big deal, but the usual term is "mash tun"...kind of an anachronism of sorts being as modern mash tuns can be made of different materials and shapes as long as they will let the wort (another term from yesteryear) drain out and leave the spent grain behind. I use a 10 gal Rubbermaid cooler, but many people also use direct-fired metal vessels...all work quite well if your grain is not milled too fine. How to Brew by John Palmer covers mash tuns in pretty good detail or just search "mash tun"
I think the shape only matters in terms of what you use to filter out the grains. There are steel braids (a.k.a. bazooka tubes) that work for either, false bottoms that mainly work for round coolers, and manifolds which are easier to build for rectangular coolers. So I would recommend deciding how you are planning on filtering the grains (I went with a false bottom because I'm lazy) and choosing based on that. (Note that the total volume is important as you don't want the grains spread too thinly otherwise they don't do a good job of filtering.) In terms of what works best, you will find as many opinions as possible configurations. My guess is that each setup has a particular strength depending on what types of grain you use, your crush size, sparge technique, etc. I wouldn't worry about it as no matter what you pick there's plenty of room for tweaking.
I use a 10-gallon Rubbermaid with a copper manifold designed after reading the How To Brew section on mash tun geometry. Converting it was pretty simple with a kit from Bargain Fittings and one afternoon of learning how to solder copper (easy as pie, but hackawing all of the slits in the manifold without a Dremel took several hours). I hold temps to within a degree, get great efficiency, and can run it off full speed with no channeling. Only stuck sparge ever was a grist with 50% wheat and not enough rice hulls apparently, but it was easy to get it going again and the beer turned out great. Note that how you intend to sparge (fly or batch) will play a role in deciding what kind of filtering medium you need to use, so read up on that, too. Intended batch size makes a difference, too. If you're only going 5 gallons, you can make big beers no problem. I did an 11 gallon batch of a 1.060 beer a few weeks ago, and my tun was filled to within a sixteenth of an inch of the top. Maxing out the Rubbermaid like that does make it a bit tougher to run off. You're not going to be able to make 10 gallons of a RIS or barleywine in a Rubbermaid. Here's a handy chart: http://www.homebrewtalk.com/f11/how-big-your-mash-tun-needs-123585/
Currently shopping for a cooler for a tun as well. Looking at a 48qt rectangle shaped cooler. It seems the large 10g "drink" coolers would work best but much pricier IMO. The link above says it well. 5g would hold 12lbs of grain at 1.25qt per pound. Would most say they use a higher 1.5qt raito? What if you wanted to mash out with hot water? 10 gallons minimum or a 48qt rectangle.
Perhaps you could find a better price at a place that sells them by the "ton." Sorry, I just couldn't resist – this comes from one who pronounced "wort" like the pencil eraser growth people get on their hands and feet for more than 2 years.
The ones at home depot go on sale from time to time for a pretty reasonable price. As far as I can tell, rubbermaid made them the same exact product but just branded it for them. The lid is hollow, though, so drilling some holes and pumping it full of Great Stuff foam insulation helps out with that.
In order to mash a ton you need 785 gallons of space. Good luck to you. More seriously, I started out with a 48qt rectangle Coleman extreme that worked fine. After a few years it was not holding temp as well, and I wanted the option to do 10 gallon "big beers" so I replaced it with at 70qt. Used the same copper manifold from the old cooler and it works just fine. Brewers use the cylinder drink coolers, but one thing to consider is the grain bed depth. A taller depth increases the chances of a stuck sparge. YMMV.
If you're planning to batch sparge, make your life easy and go with a rectangular tun, with a stainless steel braid. Go bigger than you think you'll need, because someday, you will need it to be bigger.
