Homemade Wort Chiller

Building your own wort chiller

NOTE:  I made this chiller several years ago.  The price of copper has increased so that it is difficult to make your own chiller for less money than you would spend buying a new one.  Shop around for 3/8 inch copper tubing if you want to make your own chiller.

The parts list is pretty simple:

copper tubing
adapters to attach the chiller to a water source

A quick note: you can click on any image on this page to see a much larger version.

First of all, I went to Lowes (http://www.lowes.com) and bought 50ft of 1/4 inch OD (outer diameter) refrigerator tubing for $10.78.

Why this size? Well, the smaller tubing allows for a better surface/volume ratio. However, the smaller size means a slower flow rate of water through the chiller. A larger tubing such as 1/2 inch offers a higher flow (more cool water can get in and out of the chiller) but the surface/volume ratio is reduced. Lower surface/volume means less transfer of heat between the hot wort and the cool water in the chiller.
There are other tubing sizes out there, 3/8 offers the best compromise between 1/4 and 1/2, and was what I wanted, but the store I visited was out. Get whichever you want, the price difference is about $5.

This tubing is very soft and can kink very easily. A kink in the copper probably means you’ll have to chop up the chiller or buy more tubing, so invest in a tube bender. The bender is basically just a long spring that you slip over the copper to keep it from getting kinks. Unfortunately for me, Lowes only has the “Professional” tube bending kit for close to $8. This kit has four different sizes of benders, and I only needed the 1/4 inch. Oh well, I bought it.

You can eyeball your chiller and bend it freestyle, but I’m not that good so I used a 3-gallon keg. The 3-gallon keg was a little fatter than my 5-gallons, and I thought a little wider chiller would work better in my converted keg kettle.

I started by sliding the bender onto the tubing.

Using the bender, I slowly wrapped the tubing around the keg, pressing it into shape and keeping the coils as uniform as possible.

I continued all the way around the keg, until I had about 3 feet of tubing left to bend. I created a 90-degree bend at the bottom and threaded the remaining tubing up in and out of the coils to help create a stronger chiller.

 

 

You’ll need to attach you chiller to your water source, and my source is a garden hose (more on water sources later) so I’ll need an adapter. At first I bought a nylon hose-to-1/4 tubing adapter, but later I figured out that a washing machine hose would be perfect. I happened to have one laying around, so I chopped off one end and clamped it to my chiller’s intake. Less mess than making your own adapter, but they cost $5, so you might make your own adapter for less.

Here’s a pic of the semi-completed chiller:

Here is the completed chiller in action:

It cooled a 5-gallon batch to 75 degrees on a warm day in 24 minutes. My hose was in the sun and had hot water running through it for a little while.
I also learned not to touch the exit piping. Ouch!

The chiller worked really well, but in the summer the water coming out of the pipe was too warm for effective cooling.  I ended up building a prechiller using more pipe and placed the prechiller in a cooler full of ice (with the water running to prevent freezing up).  The prechiller really helped get a nice cold break.

The Prechiller

The prechiller was made of the same type of tubing, just less of it.  It was also made much smaller so that it would fit into a small cooler.  One important lesson from the prechiller – don’t put it in the ice until water is moving through it.  On my first run it froze up right after startup and I had to thaw it out to get water flowing into the chiller.

Here you can see it compared to the chiller itself.  I connected the two with some spare high pressure keg line hose I had laying around.

Here is a shot showing the hookup to the hose.  The prechiller is sitting in a cooler full of ice at this point.

Here you can see the chiller in its ice bath.  I put water and ice into the cooler to ensure thermal conductivity.  When it was running I had ice all the way over the top, I kept the level low for this photo only.  As the ice melted I poured it out and replaced it.

The complete shot showing the path the water takes from the prechiller to the chiller and out to the ground.