Monday, July 19, 2010

New mash tun

I decided my next piece of brewing equipment would be a new mash tun so I started looking around for a good price on an appropriate vessel. I found a new 10 gallon rectangular chest cooler for $20 last week so I picked it up and started the build on Saturday.

I wasn't quite sure what design I wanted but this was definitely going to double as a lauter tun so I needed some sort of filtration system. Rectangular false bottoms are tough to find and fairly expensive so that was out. I originally headed to Lowes figuring I'd use a steel braided hose for filtration but after I got there I decided to build a PVC manifold instead.

I grabbed some 3/4" PVC pipe, 4 corners, 1 T, and a cross adapter for the manifold. I built an exterior rectangle with an output tube down the center. This fit almost exactly through the hole in the cooler and perfectly matched the interior size of the gasket that came with the cooler so I reused the gasket and used some Gorilla glue to seal, support, and insulate the PVC. This design seems to be pretty water tight. Although it is not as mechanically stable as I would like it saved me a bunch on the bulkhead so I think I'll stick with it for now and see how it holds up.

I drilled a bunch of 1/8" holes in the top and sides of the manifold for filtration. I ended up with a stuck sparge a couple of times so I might need to widen them a little bit next time.

An inline ball value connects to the output PVC and a 90 degree plastic PEX barb is a perfect attachment for a plastic hose and is easy to unscrew for cleaning.

I let everything cure overnight and brewed my first batch on Sunday, a citra pale ale. I calculated my efficiency and figure I hit about 80%. My collection volume was a ballpark estimate so this could go a few percent either direction but even low balling at 75% is pretty good for a batch sparge. It was reasonably easy to clean and can double as a chilling vessel if I need to drop wort temperature down really low for lager brewing. Overall I'm pretty happy with the new tun and at about $50 it was a real bargain.