If you homebrew, one of the most useful tools you can have in your kit, is the wort chiller. This, put simply, is a coil of copper tubing that sits in your wort, and takes the heat away. There are two main advantages to using the wort chiller. Number one, it cools the wort from the boil temperature to your pitchable temperature much quicker, and thereby reducing the time that the wort is in the “danger zone”, and at risk for infection or contaminants. Number two, it speeds up your total brew time dramatically. Most properly constructed wort chillers will take your wort down to pitchable temperature (70-75 degrees typically) in 15-30 minutes.
There are two general types of wort chillers. The first is the immersion chiller (the device sits in the wort, and cold water is pumped through the copper to remove heat). The second is the counterflow chiller (the wort is pumped through the copper coil in one direction, and cold water is pumped in the other direction in a surrounding coil of tubing, typically rubber). The instructions in this post will be for an immersion chiller. It is less expensive to build, and eaiser to keep clean, as you just put it in the pot with about 15 minuts to go in the boil.
In order to build your immersion chiller, there are a few items youll need to pickup from your local hardware store. The first, and most important item is the copper. Youll need a minimum of 25 feet, 50 is ideal. And the diameter of your tubing should be 3/8″ OD as this allows the best compromise of surface area in the wort versus flow of the water inside. This is the most expensive peice to the wort chiller.
When you buy your copper, hopefully, it will be coiled somewhat already. Mine came in this nice neat box and already had most of the shape i was looking for. You can also purchase a copper bender, which will help you prevent kinks when bending. If you do get a kink, youll need to cut the copper and start over, as your water will slow down and not allow efficient heat transfer. So, depending on your tube bending skills, you may or may not want to purchase the extra tool.
Pull your copper out of the box, and stretch it a little vertically to make a long/tall coil of copper. Then find something cylindrical to wrap your copper around, and help create a uniform coil. (i started with a paint can, but it didnt work so well so I switched to a small CO2 tank I had, which made the perfect coil.
Note the vertical peice with the 90 degree upturn at the bottom of the coil. Dont forget to add this, as you will not want your connectors, in or out, to be inside your wort.
Once you get the coil you are looking for, you should then solder on your connectors. I used a small propane blowtorch and regular plumbers solder to make the connections. Put one on each end of the tubing. Now that you have your connectors on, and your copper coiled, slide the cylinder in the tubing, and fine-tune your copper coil so that you have as much copper as possible in the wort. Your in/out connectors need to be angled and long enough so that they can rest outside of the wort pot. If one of your connectors springs a leak, you dont want that water in your brew!
To use your chiller, youll need a short peice of hose for the output (a washing machine hose works great). This hose will go in the drain of your sink, or on the ground outside, depending where you are using the chiller. For the input, simply connect a garden hose from the kitchen sink, or an outside spigot, again depending on where you are using your chiller. Place the chiller in the brewpot with about 15 minutes to go in the boil and it will sanitize anything on it. (its a good idea to keep it fairly clean all the time though) Once your boil is complete, turn the hose on high and cold, and wait. Your tap water normal temperature will also help determine the rate of cooling you will observe.
There you have it, a DIY Wort Chiller!