Happiness is a Cold Homebrew

A couple months ago, I set out on a quest to build my very own mash-tun for the purpose of brewing my first beer entirely from grain,  no extract or other shortcuts allowed. Today, I have finally conquered that quest, and I’ve decided to create a post showing how I did it. Hopefully, others that are on the fence will be inspired to create something similar and get started on brewing their first batch entirely from malted barley. Here we go…

Step 1: Bought a large chest cooler from Target for just under $22. Not too shabby. This one holds a total of 52 quarts of liquid, likely more than I’ll ever need, but the option to brew big beers like 2x IPAs and imperial stouts was important for me.

Step 2: Removed the plastic spout that was attached to the cooler. I replaced it with…

Step 3: A series of connections and fittings designed to allow the flow of sweet wort at an adjustable pace. Here you can see (from bottom right to top right) a 3/4” ball valve, a barb that fits on the end of said valve that allows for the connection of any tubing, a 3/4” compression fitting for the manifold inside the cooler, a 1/2” stainless steel washer, a #14 O-ring, and a 1/2” rubber washer that was cut to keep it compact.

Step 4: I fit the washer and O-ring onto the compression fitting that goes to the inside of the cooler. The O-ring fits up against the wall of the cooler and the washer up against the nut on the compression fitting. This keeps any liquid from escaping when draining the inside.

Step 5: I then fit the rubber washer over the compression fitting on the outside of the cooler, attached the ball valve and then tightened using a crecent wrench. Voila! Instant water-tight seal!

Step 6: The design of this mash-tun allows liquid to escape but does not allow any of the grain to get into the brewpot. I accomplished this by cutting several lengths of 1/2” copper pipe to these lengths (from right): (3) 6 3/4” lengths, (4) 5” lengths, (2) 4 1/2” lengths, (2) 3” lengths, (1) 1 1/2” length, and (1) 1” length. Whew! That’s a lot of cutting. I used a circumferential pipe cutter to make sure all the cuts were even and then cleaned up the edges with some coarse sandpaper to remove any barbs.  Up top you can see all the fittings needed. There are: (4) 90 degree elbows, (5) T-fittings, and (1) 45 degree elbow. These all fit together without any welding for easy cleaning.

Step 7: Next up, I cut several small slits in all but the two shortest pieces of copper pipe. I did this using a hacksaw and a workbench clamp. You’ll need to cut only about 1/3 of the way down into the pipe. This allows liquid in, but keeps any grain particles out. This process is called “lautering” and actually makes this vessel a combination mash/lauter-tun. Fun fact!

Step 8: The best part! Fitting all the pieces together was a breeze once I got all the cuts done. Here you can see the larger 6 3/4” lengths running along the middle, and the two smaller 3” lengths joined by a T-connection at the far right. This is also where the 45 degree bend goes to link up with the compression fitting for the outflow. Note that the slits will actually be on the BOTTOM of the cooler, not facing upwards. This manifold is also  known as a “false-bottom”. There are many different types of false bottoms, this is merely one variety. You may find that a mesh screen or other system is more suited to your needs. If so, feel free to deviate from my method. There are so many great ways to make great beer, so experiment!

Step 9: This is the connection for the outflow. I used the small 1” length to connect the T-fitting and the 45 degree bend. Then I used the 1 1/2” length, which I sanded down at the end with some rough sandpaper, to connect with my compression fitting.

Step 10: Here is the connection to the compression fitting, which then runs through ball valve for the outflow.

Step 11: And here’s the whole thing put together! Note that any oxidation on the outside of the pipe was due mainly to me testing the mash-tun with a cooler full of warm water to test for any leaks. So far, it’s looking pretty good. I’m going to soak all the copper in a 1:1 solution of water and white vinegar to remove any oxidation. That should make it nice and shiny!

The total cost for this whole project was around $60 bucks. $22 or so for the cooler, $20 for all the copper and the fittings, and another $19 for the ball valve, compression fitting, and washers/O-rings. I apologize for the length of this post, but I hope it proves helpful for those of you thinking of making the leap to all-grain brewing. Happy building, and cheers!!