As a home brewer, you are probably already aware of the importance of cooling your beer as quickly as possible. It creates a better cold break, helps reduce hazyness, and decreases the chance that Diacetyl will be introduced, which can provide an off-flavor to your brew.
But there are many ways to cool beer down to the optimum temperature. Most beginning home brewers start by using the “ice bath” method of simply putting their brew kettle into a sink full of ice water. However, with a little elbow grease and a small investment, anyone can create an affordable and very effective immersion chiller.
Immersion chillers work by allowing cold water to pass through a copper coil that is placed into the boil kettle. The rate at which it chills the wort is based on the surface area of the chiller, the temperature of the chilling water, the rate of flow through the chiller, and the amount you agitate the wort while it is chilling. For a detailed description of how and why chilling is important, you can check out this Brew Your Own article.
What You Will Need
1) 25-50 feet of either ⅜” or ⅝” OD copper coil. The longer and wider, the more it will cost, but the faster it will cool your beer (more surface area). Can be found at any hardware store. (Sears has some great prices right now!)
2) 4 stainless steel hose clamps (Hardware store)
3) About 6-10” tubing with the same inner diameter as the outer diameter of your copper coil (Local home brew stores have plenty of this)
4) adaptors to connect the chiller to a hose or faucet. Also at the hardware store. I used an adaptor that had a hose barb on one end and a garden hose connection on the other. You can also get the same thing that will connect to your sink.
How to Build the Wort Chiller
1) Find something to wrap the copper coil around. I used a 5-gallon corny keg, as this was about the size I wanted my chiller to be. You could also use a 5-gallon bucket or any other cylinder, as long as it has a diameter smaller than that of your brew kettle.
2) Wrap the copper around your keg (or other cylinder) in a tight, uniform pattern. It should go pretty easily.
3) Once the coil is formed, then take both ends and pull them through up to the top. Be careful not to kink the copper, as it is VERY hard to un-kink. The ends just need to be tall enough to reach the top of your boil kettle. No need to make them longer, as you want as much of the copper as possible to be in the wort when you use it.
4) Connect the plastic tubing to the ends of the copper using the hose clamps and tighten them down with a screwdriver.
5) Attach your hose connections to the other ends of the plastic tubing using the remaining hose clamps. Then test it all for leaks.
I then cleaned it with some PBW or B-Brite and sanatized it, but it doesn’t have to be perfect, because you will place it into your wort with about 15 minutes left in the boil, allowing the boiling wort to sterilize it.
And there you have it. A simple immersion chiller. You can usually make one yourself that is 50 feet of ⅝” for the same price you would pay for a 25-foot and ⅜” from the store. Definitely a worthwhile investment, in my opinion!