Introduction: How to Make a Wort Chiller for Homebrewing

About: Just your average handyman.

In this instructable, I am going to demonstrate how I built a wort chiller for homebrewing beer.

A wort chiller is a device that cools down wort (unfermented beer) after boiling. Cooling down wort rapidly is important because it helps to reduce the chances of bacteria from growing before you pitch the yeast. Yeast needs a certain temperature to live - too hot and you will kill the yeast, too cold and it may not ferment properly. Rapidly cooling wort is also important because it will help to discourage certain off-flavors in the finished brew.

There are mainly four methods of cooling wort rapidly. Immersion chillers are put into the wort and cold water is passed through to cool the wort. Counter-flow chillers are the opposite. They pass hot wort through cold water. Immersing the hot pot of wort in an ice bath is another way. You can also pour hot wort into cold water. The goal is to cool it as quickly as possible. Home brewers using partial-mash and all grain recipes typically find that wort chillers produce the best results.

My wort chiller passes hot wort through a copper coil submerged in a cooler filled with ice water and out through a ball valve on the side. The wort will drain out into a primary fermenting bucket where I can pitch the yeast and ferment the beer.

Step 1: Installing the Ball Valve on a Cooler

The first step is to install a ball valve on the cooler. I decided not to include instructions here since I made a separate instructable demonstrating how I did it. You can find that instructable here:

Step 2: A Word on Safety

The golden rule of making homebrewing equipment is that you should be having a tasty homebrew while doing it! I didn't make this rule, I just follow it.

However, you should make sure to have all the materials you need on hand before beginning. You don't need to be driving a car to the hardware store for forgotten parts after following the golden rule.

Step 3: Materials

Now that the ball valve is in place on my cooler, I can begin to transform my ordinary cooler into a wort chiller.

I used:
- 18' of 3/8" soft copper tubing
- (1) 3/8" compression fitting with a 3/8" male end
- (1) 3/8" compression fitting with a 3/8" female end
- (1) 3/8" brass hose barb adapter with a 3/8" male end (not pictured here)
- teflon tape

The tools I used were:
- Two wrenches
- a 3/8" soft copper tubing bender
- a drill with a 1-1/2" hole saw
- a pipe cutter

Step 4: Bending the Copper Tubing

The goal is to coil the copper into a tube that will pass through the cold water and allow the heat from the wort to dissipate rapidly. Using many coils creates more surface area for the hot wort to touch on its path through the chiller.

I used a tubing bender to safely bend my copper without any kinks. Don't be like me and underestimate how much copper tubing you will need. I ran out and had to get more and use a coupling to continue. I wound up needing almost 18 feet. Buy the right amount the first time and you won't need to worry about it.

To keep my coils relatively equal, I used a 3 liter plastic soda bottle to check my progress.

The coil itself begins straight so it can go to the ball valve. I turned it about 90 degrees to begin the coils. I made about 9 coils and then did another 90 degree bend straight up.

It's difficult to describe just how I shaped the pipe. If this step's description doesn't make sense, continue anyway and see how it will function.

Step 5: Connecting to the Ball Valve

On the inside of the cooler will be a coupling that the copper coil will attach to. Take the 3/8" compression fitting with the male end and remove the nut and compression ring. Screw the fitting into the coupling and tighten with a wrench.

Now, connect the copper coil. Slide the nut and compression ring over the tube and re-connect it to the compression fitting. Snug with a wrench.

Step 6: Making the Wort Inlet

There should be extra tubing sticking straight up out of the cooler now. I used a pipe cutter and trimmed it so there would be about four inches sticking up.

I lowered the lid and marked where the inlet would come out of the lid. I then took a hole saw and cut a hole. The four inches of tubing should stick out of the lid a bit when closed.

Step 7: Making the Wort Inlet Cont'd

Take the 3/8" compression fitting with the female end and remove the nut and compression ring. I used a pair of clothespins to hold the tube in place and to prevent the nut and ring from sliding down into the cooler.

Tighten the nut and compression ring onto the fitting and put on the hose barb adapter.

This is where the wort will enter the chiller via clear tubing that will slide onto the barb.

Step 8: Testing the Wort Chiller for Leaks

In this video, I'm demonstrating how the wort chiller will work and checking for leaks.

Soft copper and compression fittings can be tricky sometimes. If you have a leak, make sure everything has been tightened properly. This will usually do the trick. If you notice the leak is coming from the threads of a fitting, try teflon tape on the threads. I had to go back and use a little tape on the fittings.

Step 9: Using the Wort Chiller

Now that the wort chiller is in good working order, it is time to test it out. I began boiling two gallons of water to simulate boiling wort and once it was almost there, I filled up the cooler with ice water. Since I try not to waste a lot of water, I used little frozen bottles since I can reuse them next time. Ice water temperature was 55 degrees F. I dumped the boiling water into a bucket with a plastic valve. Temperature in the bucket was 204. I opened up the plastic valve and the ball valve on the wort chiller.

When the bucket was nearly empty, I tilted it to get all the water I could out. Once it was empty, I tilted the cooler a little (don't spill the icewater!) to get as much "wort" out as possible. Final temperature of the two gallons of boiled water was 84.

This worked pretty well. I could have packed a lot more ice in there and that would have brought down the temperature of the wort to within the 60's no problem. I also liked how I could use the ball valve to kind of control the temperature of the water leaving the chiller - open wider for warmer, close it more for colder. I think this will have no problem on brewing day.

And of course, if this were real wort and not water, I'd flush out the coil during cleanup.

Step 10: Wort Chiller Maintenance and Cleaning

Before using the wort chiller on brewing day, test it out to make sure all the fittings are tight and that it is clean and ready to go.

Cleaning the inside of the coil can be done with PBW (Powdered Brewery Wash). Follow the instructions on the package. Sanitize with StarSan or the sanitizer of your choice.

If there are any leaks, you should notice it during cleaning and sanitizing. Fix before using the chiller or else you may contaminate the wort.

Step 11: Summary

That's my wort chiller. I'm really proud of the design and happy with the way it works. I think it will be very useful when I step up to partial-mash and all-grain beer techniques. Be on the lookout for my future instructable where I will show how I make my mash tun.