Xtreme Mashtun Build

I finished my conversion of the Xtreme cooler to a massive mashtun. I can't take full credit for the parts and ideas as I found inspiration from others who have done similar builds.

Here's all the parts I needed:




Parts List:

• Xtreme 70qt cooler
• Stainless braid from water supply line
• #18 O-Ring (15/16" I.D.) - $1.97 (pack of 10)
• Teflon tape - $0.99
• 3/8" Flare Nut - Watts A-160 - $1.55
• 3/8" Flare x 3/8" MIP Union - Watts A-183 - $1.66
• 3/8" Panel Mount Couling - McMaster Carr 50785 K274 - $9.72
• 3/8" MIP x Close Brass Pipe Nipple - Watts A-785 - $1.52
• 3/8" Threaded Full Part Pall Valve - $6.27
• 3/8" x 3/8" I.D. Barb to MIP Adapter - $2.10

I inserted the coupling from the inside with an O-ring. I took a little force as the factory opening isn't quite big enough. I used a half round file to shave enough off to get it started. I put the lock washer and nut on the outside.

Next I put some teflon tape around the nipple and used that to connect the coupling to the ball valve. Make sure that the ball valve is arranged so that when the handle is open, it's pointing away from the cooler.


Next up I added the barb to MIP adapter with some teflon tape on it as well. MIP stands for Male Iron Pipe so that should be 3/8" to match the ball valve, but if you are using a different sized line than 3/8" you might need to get a different adapter.


I then narrowed one end of the braid by pulling it tight (think Chinese fingercuffs) so it would fit through the flare nut. Once through, I spread out the end enough to go over the Flare MIP Union and tightened the flare nut.


The braid assembly screws into the inside of the coupling. I didn't tighten too much just because I want to easily take it out in case I need to use this cooler as an actual cooler.

I left the braid at it's full length for now because I'm not sure if the extra length is beneficial or harmful for batch sparging.

Awesome Bass!

I just did this exact build this past weekend (thanks to your post) and will hopefully be doing my first AG this coming weekend.

Fantastic post! I will not get into the Ghetto rig I did on my 36 qt. X-treme cooler. Very ugly, 1/2 the price, and hasn't leaked yet. I bought a 70 qt. X-treme a couple weeks ago and have been looking for a coupling to get through the cooler similar to what you did. Your post was just in time! I bought 2 of those McMaster Carr couplings. They are just what I was looking for. I have a kick-a$$ addition to your technique, however.

To get the valve assembly out, take a 1 1/2" or 2" 5/16 hex head cap screw and double nut the end. Insert one end into the inside of the original valve, and use a ratchet on the other end of the cap screw to get the valve out. Once it is out, take a 1" spade drill bit and put the shank of the bit through the hole, inside of the cooler to outside. Attach the bit to a drill and PULL the bit through while it is turning full speed. Perfect 1" hole for the Panel Coupling.