Sunday, January 8, 2012

DIY Wort Chiller

One of the more annoying parts of the brewing process is waiting for your wort (flavored grain tea, beer to be) to cool off enough to pitch your yeast.  A device called a wort chiller allows you to greatly reduce the time spent doing this.

I'm going to do a little show and tell for the one I just built (entirely from hardware store components), but we're going to need to talk a little bit about thermodynamics first.

All materials have a property called specific heat.  This is how much energy (in Joules) which must be added or removed from a gram of the material in order to change its temperature by one degree Celsius.  For water (which even the heaviest beer consists mainly of) this is 4.186 Joules, which is a lot higher than most things.  A standard five gallon batch of beer will weigh just shy of 19 kilograms.  In order to get it down to yeast pitching temperature you will be trying to lower it from  just below 100 Celsius to around 24 Celsius.  Simple arithmetic dictates that we need to remove about 6 million Joules from your wort.

The other thing about thermodynamics is how heat behaves.  It flows from the areas with the most heat to those with the least until it is evenly distributed throughout the material.  This is why putting ice in your drink cools it off, and why the ice melts.  We're going to build a device to insert into our wort that will absorb heat from it, and carry that heat away.  This will be done by running water through tubing which has been submerged in the wort.

This is a 20' section of 3/8 copper tubing, purchased at a nationwide hardware store that rhymes with Gnome Repo.  My girlfriend and I wrapped it around our kitchen fire extinguisher (it was a two person job).  Enough tubing was left out to allow it to hang over the edge of the fermenter bucket.  We probably could've made it more uniform, but considering that neither of us had ever worked with copper tubing before I think we did a pretty good job.

Now that I had a really cool copper coil, I had to set it up so I could run some water through it.

Here we have a 3/8" Ander-Lign compression fitting attached to the end of the tubing.  A 1/2" pipe nipple then connects the connector for a garden hose.  The Ander-Lign fitting does not require a compression sleeve, you simply fit it to the tubing and apply torque.

Another Ander-Lign fitting is attached to the opposite end of the tubing.  It has a 1/2" to 3/4" adapter installed, so a garden hose can be attached to the output of the wort chiller.  This will allow the water to be used for other purposes (waste not, want not) or simply carry it away from the area.

While testing the chiller for leaks, I found it to be very cold to the touch.  I sincerely hope that it will significantly reduce the time spent waiting for my wort to cool.


  1. I'm too cheap to buy one and too slapdash to make one so I am still using ice baggies. I would have crimped my pipe.

  2. You can crimp the pipe, but not as easily as you'd think. I never had enough ice to cool it down in a reasonable period of time. The chiller got it down to pitching temp in about 30 minutes.