I recently saw a post on the “N.E. Home Brew Network” Facebook Group regarding a bargain buy from Tesco for a 52 litre cooler box for £20 – Ideal for converting into a mash tun.

After a few good brews based on Malt Extract, I’ve worked out I could be saving between £10 & £20 per brew if I was brewing “All-Grain” batches.  It seemed like a no brainer!  I placed my order and picked one up the next day.

I scoured eBay and bought a mash tun conversion kit.  The kit is basically a 1/2″  2-part ball valve, hose barb, 1/2″ nipple, a 12″ bazooka filter and a couple of washers and nuts.

The stuff’s been sat in my garage for just over a month, but today I finally had chance to have a go at the conversion!…

Measure the internal depth of the box, and make a mark of that depth on the outside. Take the nut you’ll use to attach the tap, and mark where the hole should go – As close to the bottom of the inside as possible.  Little helper optional 🙂

Drill the hole!

Check the tap + nipple fits, remove and wrap LOTS of PTFE tape around the thread.  The tape should wrap tightly around the thread in the same direction the nut will tighten!

Fit the washer, nut and tighten.  Lots.

At this point I filled with about 20 litres of hot (65C) water from the tap to test for leaks and check how long it can hold temperature for.  Unfortunately, after a few minutes I noticed a very slow leak appearing to come from the join between the outside nut & the wall of the cooler box.  I quickly emptied the box, re-wrapped the nipple with a lot more PTFE tape and tested again.  It worked!

I refilled the box with another 20L of 65C water and left it for an hour, during which it only lost 3C!  Results.

Coming soon – The new HLT, the new boiler, pumps and stuff! 🙂