Mash Tun Completed!

Last night I grabbed an hour while RAR was asleep and managed to finish the mash tun build.

The first part was relatively easy; fitting the ball valve tap. Obviously I don’t want the wort just pouring out of the bottom of the tun, so I needed a way to keep it all in and control what comes out, and how fast it does. This is important for things like controlling first runnings to pour back through the grain bed. Using the same compression fittings I used to plumb the pipe through, I attached the 15mm ball valve tap I bought from B&Q. I do have a 15mm female compression elbow to fit at some point, to redirect the flow downwards, but at the moment when it’s fastened tight it points to the right – not ideal.

Ball valve tap attached with compression fittings.

After I finished insulating the body before, all I had to do was make sure the rest of it was properly insulated, so that when I start mashing grain it holds temperature as best it can. The first, easy part was adding more of the insulating wrap I’d used for the rest of the build to the lid.

It’s not the prettiest, but it’ll do the job.

On the original Instructable that I’ve been following for the most part, the author found that he had a few inches of the internal fermenting bin sticking out of the top once it was put inside the main tun. That meant he was able to wrap more insulation around that exposed area to minimise any heat loss, so I thought I’d do the same thing. Except there was a problem…

Very shallow overhang when the internal bin is in place.

As you can see from the photo above, when my mash tun is assembled, there’s very little overhang exposed. This is both good and bad at the same time. Good in the sense that it means heat loss is lower, but bad because it gives me much less to work with to insulate it. By the time I wrap insulation around it, there’s almost no room left to attach the tape. The other problem is that I wanted to keep the handle attached to make it easier to remove the grain and clean it afterwards.

After a quick think (aided by a bottle of London Pride) I came up with a plan for a basic thermal cap. Think of it as a woolly hat for my brew. It’s a bit rough-and-ready, but it’s a good size and fit, and can be put on without needing to remove the handle.

Shiny! My mash tun’s warm hat.

So there we go, it’s finished! I’ve done a couple of quick tests for leaks, which have all been good so far (no drips anywhere!), and once I get a decent thermometer I’ll do some tests for heat retention, but all being well, I’ve finished.

Completed mash tun

…and another picture of the completed tun.

It’s taken a couple of weeks to do what I could have done in a day or two if I didn’t have a little boy invading every corner of my life, but to be honest, I quite like the slow build. There’s no rush after all, and I don’t even have a boiler yet. The longer I wait, the more time I have to decide what I’m going to brew, and how to do it. That said, I can’t wait to taste the first pint.