When making the transition from extract brewing to all grain brewing, the main piece of equipment that is usually missing from a home brewers arsenal is a mash tun. If you’re already brewing from extract, chances are, you probably have most of the other equipment you need. Converting a basic 5 or 10 gallon beverage cooler to use as a mash/lauter tun is the easiest and most economical way to make this transition.
A mash tun is what you use to infuse your crushed grain with water and allow the various enzymes to go to work at breaking down the starches in the malt into fermentable and non-fermentable sugars. Thing is, once you get the those enzymes to work and they’ve done their jobs, how do you separate the liquid from the grain? Well, there are a few different options; one is to use a false bottom, which is essentially a screen that sits on the bottom of the cooler and creates a pocket where the liquid wort can collect without allowing any of the grain in. You can then have a dip tube tap inside that area which will then connect to your ball valve where you can drain the wort off. Another way is to use a type of “Bazooka Screen” which is essentially a mesh tube that filters the husks and other matter, allowing the wort to pass through. I’ve seen people make them out of the stainless steel braiding that comes on the outside of a standard faucet supply hose. I’m a little suspicious of this approach because it sounds like it could collapse pretty easily under the weight of the grains, but perhaps you could insert some kind of wire to help prevent that. Yet another way, is to create a network of copper pipes with thin slots cut into it. This ‘manifold’ would allow the wort to seep into these slots and flow through pipes to the ball valve without allowing the thicker grain particles to enter. On both my 5 gallon and 10 gallon systems, I chose to go with the last option. Mainly because I can source the needed materials from any local hardware store, it’s incredibly sturdy, reliable, and I can make it myself.
I’m going to take you through the process of making one of these copper manifolds for use in a Coleman 5 Gallon beverage cooler like the one I bought from my local Canadian Tire for $39.99. ( also found a similar one by Rubbermaid at Home Hardware for $44.99 if you can’t find the other one) If you’ve chosen to use a different type of cooler, the manifold is essentially the same, you will just have to size it appropriately to fit yours. The important thing is to have the majority of the pipes flowing towards the outlet valve. Having them this way will help the wort drain easier as opposed to having them run perpendicular to the outlet valve.
To start, we’re going to need the following copper parts:
- 4 x 90 degree elbows
- 6 x ‘T’ joins
- 1 x 1/2″ end cap
- 1 x 1/2″ sweat to 1/2″ FPT (to join the manifold to the threaded pipe nipple & ball valve. Choose the appropriate fitting for your system)
- 1/2″ copper pipe – you can usually by a 3′ length of it which will be enough
From the 3 foot length of pipe, you will need to cut the following pieces:
At this point you can ‘dry fit’ the pieces together and see how it sits in your mash tun. If you need to shorten any of the lengths, now is the time to do so.
A NOTE ON SOLDERING:
First off, BE CAREFUL! You’re working with an open flame. If you’re not comfortable using a torch, or you’ve never soldered before, please ask for help or get someone who knows to show you how. There’s enough chances to be burned while brewing, we don’t need another chance here!
Secondly, the single most important thing after safety is to make sure the pieces you are joining are 100% clean. If they’re not, you are just wasting your time and will make a blackened mess. My suggestion is to soak your pieces in hot water and Oxyclean (or PBW) for about an hour to get all the price sticker goo off and clean whatever else was on them.
- Propane torch
- lead free solder
- lead free acid flux paste
- a brush for the flux
- medium/fine grit sandpaper
- an optional tool for sanding the inside of the pipe (this is money well spent and will save your fingers the pain!)
We’re only going to solder together the horizontal joins that connect the ‘t’ fittings. Leaving the longer straight pieces separate will make cleaning much easier. Make sure you have your fittings lined up straight before you solder them! Lay them down on a table and make sure they stay that way. If you need to, take a pair of pliers and squeeze the 1/2 pipe very gently to warp it, this way it should prevent it from spinning once in place. You can hold the parts in a vice or possibly stand them up on a non-flammable surface. They need to be 100% straight or the longer pieces may not line up and you’ll have to unsolder everything or start over. You could also loosely fit everything together and then solder the places you want, but you run the risk of the solder getting into joins that you don’t want it in. Be sure you have proper ventilation if you’re not doing it outside. We don’t need you passing out and burning the house down! Use a medium to fine grit sandpaper to rough up the outsides, and the optional tool for roughing up the insides of any join. This will give the solder something to stick to. Apply the flux paste immediately after doing this. Also, with joins as close as these, you’ll need to leave a small gap, about 1/32″, to allow the solder to get inside. Solder both sides at the same time because you’re heating that area anyways. (You may already know all this, but in case you don’t, I have to say it, because we don’t want anyone getting hurt!)
So we’ll start with the back section. The first join will look like this:
Secondly, we’ll do the same for the other side:
Lastly we’ll join the middle:
We’re going to leave the small piece off the back un-soldered to help with cleaning. You can solder the end cap on if you like, or just keep it as a dry fit. I will solder mine, that way I can get a few extra slots cut into it.
Do the same for the front section.
Again, for the part that joins to the threaded female FPT, I’m not going to solder it to the main frame, only to the 1/2″ pipe. (as shown above) This way when we put the manifold into the cooler we will be able to screw it on to the pipe fitting that comes through the cooler wall.
Once we’re finished the soldering, we need to cut the slots into it. I’m once again lucky that I have access to a band saw here at work, which makes this part a million times easier. You can do it with a hacksaw if that’s your only option, but I’m sure it will be an unbelievable pain in the butt and may not look as nice. Ask around to people you know and see if anyone has access to a band saw. If a hacksaw is your only option, then you’ll just have to make it work.
Insert the long pieces into the soldered sections and mark how far it goes in. (There’s no sense in cutting slots where it’s going to be inside a fitting.) Then cut slots in the long straight pieces and along the soldered sections. You want the slots to be on the top half of the manifold, (although they will work on the bottom) and only cut 1/2″ through the pipe obviously, otherwise you’ll just end up with a bunch of pieces!
Once done, clean off any burrs with a file or sandpaper, give it a good solid soak in hot water and Oxyclean again.
You can also give it a quick boil in vinegar to go that extra mile, and voila! You have a copper manifold for your mash tun!