BeerBorg

I was having a hard time doing 5 gallon BIAB batches, so I decided to convert a cooler to a Mash Tun. I’d had this cooler for about 10-15 years or so. Picked it up at a garage sale and only used it a couple times. Now it gets to have a new purpose in life. My cooler was a bit different size wise from most of the instructions that I found online, so I had to use some different sized parts to make it work.


This is a 10 gallon Coleman cooler with markings on the inside for both gallons and liters. Lucky me!


Very easy to remove the spigot. Make sure you save the inner rubber gasket. You will need it to seal properly.


The size of the hole and thickness of the wall was a little bigger than I expected, so I had to return the 3/8” parts I was planning on using (from instructions on HBT), and get 1/2” parts. Here is the parts list I ended up with:

½” threaded ball valve
½” barb x ½” MIP hose adapter (2)
½” barb x ½” FIP hose adapter
½” MIP x 2” brass nipple
¾” fender washers (4)
¾” ID O-ring (4)
½” CPVC transition adapter
½” CPVC 90 degree elbow (4)
½” CPVC tee (3)
½” CPVC pipe
Teflon tape

First, I attached the ball valve to the 2” brass nipple, then one of the MIP hose adapters to the ball valve. Make sure to use Teflon tape on all the treaded joints to prevent leaking. After a few test fits through the cooler, I found that I needed 3 washers on the outside of the cooler for spacing.


I ended up using 4 of the O-rings on the brass nipple between the inside and outside of the cooler. That gave me the best seal, but I’ve seen some use only one. Then I attached the FIP hose adapter to the inside end of the brass nipple using one washer and the original gasket from the cooler. Got it nice and tight and filled with a couple gallons of water to check for leaks. So far so good.


Now it was time to build the CPVC manifold. I sized it to fit about and inch from the sides, and drain from the center to help reduce any channeling of the wort down the sides of the cooler. I used a hack saw and miter box to cut the slots in the CPVC pipe, and the joints are all just slip fit so it can be taken apart for easy cleaning.


Then I attached the CPVC transition adapter to the center tee, and added the last MIP hose adapter. A short length of ½” ID hose connects the two hose adapters together.




Time to test the full system. I filled it with 5 gallons of water, and let it sit for an hour.


No leaks!! I drained the water though the manifold and ball valve, and that worked great. Looked like a good flow rate to me. After it drained, there was only 1 cup of water left in the cooler!

If you are thinking about making one of your own, go for it! You may need to adapt some of the parts for whatever cooler you have, and be a little creative on connecting the manifold, but it is a pretty straight forward project. This was a lot of fun to build, and it works great!

Definitely bookmarking this one. It's something I've wanted to do for a long while, but I need to upgrade my brew pot before doing this. I can only accomodate 2.5 gallon batches right now with my current equipment.

Awesome job on the mash tun. I thought of going that route but went to a bigger pot and stuck with BIAB brewing as I've got my system pretty much where I won't it.

This could be a sticky!

Beer-lord wrote:Awesome job on the mash tun. I thought of going that route but went to a bigger pot and stuck with BIAB brewing as I've got my system pretty much where I won't it.

This could be a sticky!

BAM, Stuck!

Cool! My first sticky thread!

Alright, so I am new to these but keeping my eye out for when I decide to upgrade my brewery (if all goes well, Christmas-time!). I have seen a few posts about making these, and one I remember talked about a false bottom, but you don't use one. If I gather correctly, you just sawed grooves in the CPVC and then installed it groove side down. Does this help drain the water, but not the grain? How well does this work, because this looks like an easy conversion!

There are 3 common "drainage" systems for a MT.

1. SS Braid or "Bazooka" type screen
2. False bottom
3. Manifold

You can DIY a braid and/or manifold, but a false bottom is something you should buy. People use all three types (and probably others) and have good results. Depends on how you want to do it. I chose the manifold because it covers a larger area than a braid, and unless you reinforce a braid it has a tendency to collapse. Since my cooler is square, a traditional false bottom wouldn't work, and they can get pricey for a serial DIYer.

I cut the grooves almost halfway through the CPVC (you can also use copper pipe). Installing it upside down has two benefits. First, it helps to keep it from getting a stuck sparge as the weight of the grain isn't directly on the opening. Second, since you have a siphon going when draining the MT, having the slots on the bottom leaves less liquid in the MT than if they were on the top.

It is a pretty easy conversion. Just make sure you size the parts appropriately for the thickness of the cooler and diameter of the drain hole.

Very similar to my build, although I used a 5-gallon round cooler I bought at Home Dopey. But the fittings and the manifold are pretty much identical. Nice job!

Nice write-up! Very nice tun! I did one up using a 10 gallon round cooler and a stainless steel bazooka. I need to make a smaller one to use for steeping.

Very nice...I use a similar manifold only in a 10 gallon round cooloer:

Fully Assembled: Apart to Clean: Inserted into Tun:

Woohoo, I picked up a cooler today off a craigslist ad. 5 gallon one for 10 bucks, so it'll let me do full volume mashes for my LBKs. Hope to pick up the hardware to convert it relatively soon.

Sooooo I finally finished rigging up the spigot, but haven't configured a filter of any kind yet. Would a filter be necessary, or can you just recirculate the wort over the grain bed, using the grains as a natural filter, until the wort runs clear? If anything, I can just use my BIAB bag to hold the grain and filter the solids until I can get a bazooka screen or something.

Personally, I wouldn't run it without some sort of filter. Without one, you will most likely get grain particles or husks in your BK. Don't want to boil those.

BIAB bag might not be a bad short term idea. Would make clean up a LOT easier too. However, if using the bag, you may as well continue to BIAB. Why add the extra step...

Yeah, that's the whole thing, I'm trying to not use the bag anymore, but finances were keeping me from buying everything all at once. I sacrificed buying some parts for the conversion in order to buy ingredients to brew. The biggest advantage right now w/ the tun and still using the bag is to make higher gravity beers I couldn't do in the pot because of its size.

philm00x wrote:Yeah, that's the whole thing, I'm trying to not use the bag anymore, but finances were keeping me from buying everything all at once. I sacrificed buying some parts for the conversion in order to buy ingredients to brew. The biggest advantage right now w/ the tun and still using the bag is to make higher gravity beers I couldn't do in the pot because of its size.

Uhhmmm EXCUSE ME but you are busted. You have been caught not only posting outside of SMEIBBs Corner but actually speaking in non-SMEIBB tongue. This is blasphemy and MUST stop.