Switching to All-Grain Brewing: Building My MLT

I want to first say that I take absolutely no credit for the design of this MLT (mash lauter tun).  All of the ideas/instructions came from this post by FlyGuy on the Home Brew Talk forums.  I highly suggest checking reading through the thread.  There is a lot of great info there.

I made a few modifications of my own (such as using this mash screen from Northern Brewer).  I had a lot of fun building it so I figured I would share my experience.  Hopefully it inspires others to leap in to all-grain brewing and build their own.

First: Parts.

I found most of what I needed at the local Home Depot in Mira Mesa.  Where possible, I linked to the product page.  I found it useful to know what I was looking for before heading in to the hardware store.  Here are the parts I used:

Total:  $69.20  Now compare that to some of the pricey conversion kits you find such as the one here ($300) or here ($180).  Now granted both of those kits are for TWO coolers, and include a false bottom instead of mash screen, but you are still saving money.  I decided to batch sparge instead of fly sparge so I only need one cooler.  This frees up some cash for other goodies such as a propane burner or a nicer kettle.

* I couldn’t find 5/8 washers at Home Depot…YMMV

** I quickly learned from the Home Brew Talk forums as well as my own personal experience that the 5/8” stainless steel washer would be the most difficult to find.  Every Fastenol store was sold out of them.  They ordered 2 for me and had them available for pickup within 2 days.

Here are all of the parts (minus the mash screen):

Step One:  Take the spigot off of the Rubbermaid cooler.  Keep the white seal on the inside of the cooler.

Step Two:  Apply teflon tape to the threads on the nipple, the mash screen and the male barb adaptor.

Step Three:  Attach the male barb adaptor to the 3/8 ball valve and the mash screen and the brass coupling.  Remove any excess teflon tape.

Step Four:  Using a pair of pliers, crimp and curl the edge of the mash screen so that it will fit inside your cooler.  

Step Five:  Screw the coupling to the brass nipple.  Slip the stainless steel fender washer over the nipple.  Insert the seal from the plastic spigot from the inside of cooler and insert brass nipple inside.

Step Six:  Pull the brass nipple all the way through the hole in the cooler, and insert the O-ring.  Add 5/8 washers to ensure a tight fit once the ball valve is installed.  I needed 4 washers, but others have reported needing more or less.  Now screw on the ball valve and tighten as best as you can to ensure a seal. 

How it looks from the top:

Step Seven:  Fill your fancy new MLT with 5-10 gallons of water.  Check to see if there are any visual signs of leaks.  Now let it sit for about an hour an see if you can spot any leaks.  If there are leaks, I suggest trying more O-rings, additional washers, or just tightening up everything.  I had a leak at first but adding a washer and tightening things up seemed to fix the problem.  If you still have problems after these suggestions, check out the original thread for this on Home Brew Talk

BAM!  Done.  I haven’t brewed with this yet, but I plan to next week.  I am pretty excited to leave my partial mash ways behind and dive in to all-grain brewing.