Brewing for the Impatient: your mash tun

I cannot believe how long it took me to build my mash tun. In then end I think I was a bit intimidated, partly because I didn’t really understand what a mash tun was. Whenever I set down to research it, I’d end up on some long-winded analysis of manifold efficiency and sparge mechanics. What I’ve since learned is that a mash tun is a container that keeps water and grain at a stable temperature. That’s it.

To build an effective mash tun, you need to consider only a few simple things:

Stable temperature
extract water from mash tun (aka spigot/valve)
filter grain from water
capacity

Don’t get me wrong, you can derive path lengths, surface to volume, gravity and pump feeds, and whatever else you feel like. Later. But if you want to git’er done today, that’s the meat of it.

Here’s a look at the mash tun I built. You can probably do it simpler, since I managed to lose the spigot fittings. In fact, a conversation with Michel Brown inspired much of this, and his suggestion was to take a simple rectangular ice chest and fix a piece of steel wool in front of the spigot as a filter. That’s not what I did, but it sounds like a solidly impatient way to go.

I started with a typical 10-gallon orange round igloo-style cooler. I removed the spigot and lost the pieces after two moves.

Here’s a photo of the pieces I used:

The parts are all 1/2″. The tubing is a piece of braided stainless steel 40″ washer tubing with the rubber piece removed. I used a hacksaw to cut the ends off and then pushed the braided steel over the rubber hose (rather than pulling) while holding the hose with needle nose pliers. Note that many of the washing machine hoses are actually a polymer, and I’m not entirely sure if it matters a bunch. They look almost identical, though the polymers appeared to have two thicker threads per braid whereas steel had four.

And here’s how they fit together:

The washer indicates where the cooler wall goes. The parts are all 1/2″. I used two o-rings per side and compressed the heck out of them to get a good seal.

The final pieces screwed into the T-joint and I collared the braid onto them.

When everything is assembled, test it. Fill it with water and let it sit for 45 mniutes. Then do it again with hot (170 deg F) water. Close it up and let it sit. There should be no leakage.

PS. Why no equipment list? Invariably something is unavailable or hard to find, and that always mucks up the works for me. But you can find detailed instructions here or here.