Simple rectangular cooler conversion

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Images and instructions for converting a rectangular cooler to a mash tun.


Simple and Inexpensive Rectangular Mash Tun

A mash tun (or lauter tun) can be made very inexpensively by converting a rectangular cooler for the job.

All you would need is the following:

One 48 qt or large rectangular cooler (mine is a Coleman brand)

One #2 stopper

One bottling spigot

Three feet of 3/8 soft copper tubing
Was looking at using some cold water PVC piping for mine as I have enough lying around from a recent plumbing job to put water into my shed for brewing. Shouldn't make any difference over copper should it?

The only issue I can think of with PVC is the temperature rating. I'm a bit vague on this but I think there's PVC and CPVC and that CPVC is rated for use at higher temperatures (up to around 82 degrees celcius I think). Anyone know for sure?

Other than that people have constructed manifolds from pvc with great results.


I've also read that using a dremel rather than a hacksaw will minimise burring in PVC (which might create irritations with bits of grain/husk getting stuck in your manifold).


vindaloo edit - merged posts
OK, what is the simple way to tell the difference between PVC and CPVC? Is it written on the tubing?

Ok, got the pvc tubing today and the elbows. However the only t-pieces I could source were ones with inspection points.
Anyone know where I can get t-pieces in Sydney without inspection points (preferably in the North and North-Western suburbs).
I still have a couple of days holiday in which I can get around to get bits and pieces.

bugger bugger bugger.
Just realised I got UPVC and not CPVC :angry: :( ;) .
Where the hell can you get CPVC .... plumbing supply stores :huh: ?

Try tradelink. Look in the yellow pages for one near you. The only one I know of is at Wetheril Park.


Ok, I now have temp. rated tubing, and connectors.
Been reading up on mash tun design to get the right geometery for the manfold.
In the mash tun design section of How to Brew, it is stated that the manafold should not touch the sides of the cooler.
I've seen a number of pictures however where this is the case. Are these simply bad implementations.
Has anyone built a mashtun where it does, and subsequently changed your design because of a low extraction rate?

OK, got all the plumbing sorted last night.
The esky conversion is almost complete. The manifold is built.

Tonight I will either cut slots in the under side or drill holes.

What do you guys recommend?
While drilling holes will be easier, I will do slots if that will provide a better result.


Well, as per the fantastic response :( , I went with holes.
Here is the manifold upside down.

And showing the outside of the Esky with the tap.
I actually have another bit that screws on to the tap with an elbow in it and enough tube to reach the boiler.


I know its off topic - but in the last shot, its great to see the beer in the photo - atleast you have some insperation to get it done :)
In fact you can also see the dart board over the left top corner of the cooler too. :D

These pictures are terrific. Can you send me a parts listing for your bulkhead replacement/tap setup?

I've no idea about the slots/holes question, so I just posted a question to rec.crafts.brewing - hopefully we'll get some replies.

Keep us updated on how you go - it looks like a great setup.

The parts listing is a bit of a mystery to me as my father-in-law is a plumber and he took care of it, when I told him what I was after. Sorry if the names of the bits aren't correct.
All the connectors have the compression fittings. You need a special tool that tightens the copper sleeves around the fitting to keep it all together.

Bascially though:
5 elbows (the 5th one goes on the external pipe that screws onto the tap (not shown in pics),
2 T-pieces
1 reducing t-piece
2 pipe/tube to 1/2 thread connector (one for the internal, and one for the external (ie. other side of the tap (not shown in pic)))
Length of 1/2 inch thread
1 gas ball and cock tap with internal thread one end and external thread the other.
2 back nuts
1 washer
1 length of larger diameter pipe (internal manifold)
1 length of smaller diameter pipe (external tubing that connects to the other side of the tap (not shown) and for the small piece that connects the t-piece to the thread at the drain.

Total cost, one carton of duty free cigarettes :p

I think that is the lot.
Hope it helps.

Thanks Reg,

Looks like I didn't go too far wrong.
I did try to keep the holes off centre on the side runs to hopefully minimise the path of least resistance as document by John Palmer in How to Brew.
However I did deviate from his design of leaving a space between the manifold and the side of the cooler because it just wasn't practical with the materials I had.
Should work well. Fingers crossed.
I did also do some temp tests on it and it only dropped 1.5DegC from a starting temp of 66.5degC in 66mins. Then it dropped another degree in the next 35 mins, although it would have lost some heat from me opening the lid to measure the temp.
Should be fine.


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