Our original wort chiller was a 25′ copper immersion chiller that we acquired through part of a Craigslist purchase. While it certainly did the job and was better than not having one, we were ready to have better cooling capacity since we were interested in lagers and needed to reach lower pitch temperatures, as well as minimize the cold-side open air contact with the wort.
Since OSH was going out of business, we were able to get 50′ of copper tubing and create a new immersion chiller easily and on a budget. We probably would have done it sooner if we had known how easy it was, but even with no planning this all came together in a single afternoon. We used it for the first time the next day and were able to get to 46 F with the same amount of ice that typically gave us trouble getting down to 70 F.
Our requirements were having 3/8″ hose barbs on either end of the tubing, but also allow for later adapting to a hose or other pump setups. Because of this, we wanted a 3/8″ FPT that made it easy to swap out the end piece. For now, we also put a 3/8″ hose barb on the end. You can skip all of that if you just want to hose clamp your PVC tubing onto the end of the copper tubing.
- 50′ of 3/8″ copper tubing
- 3/8″ compression fitting with 3/8″ FPT / FIP
- 3/8″ ID ferrule compression sleeve
- 3/8″ MPT / MIP to 3/8″ host barb
- 20′ or so of 3/8″ PVC tubing
- 3/8″ hose barb to 3/4″ FHT garden hose adapter (optional)
- Stainless steel hose clamps
- Keg or other similar size sturdy cylinder
- Wrench or pliers
- Take one end of the copper tubing and gently begin to form it around the shape of the keg. This is easier with two people if one is shaping it around the keg and the other is feeding it to person 1. Be gently with the copper, it’s soft and can crimp easily.
- Form a coil as tightly as possible leaving about 15 to 20 inches at the end (depending upon your kettle size).
- Very gently and gradually bend the end upward so that it will be pointing out of your kettle. Make sure not to just bend at one point, bend gradually by shifting the bend point. Use your thumbs to form a focal point that you are pushing on. Move when the copper gives slightly. Do not crimp the copper.
- Take about 4 inches at the end and bend that so that it will “hook” the edge of your kettle. File down the end as needed.
- Repeat with the other end of the coil.
- If you are installing the compression fittings, put the nut onto the copper, then the ferrule, then push the compression fitting against the end of the copper tube and then screw the nut onto it. Use the wrench/pliers to tighten about 1/4 of a turn at a time. Make sure the nut is straight to prevent leaks. Repeat for both ends.
- Add a hose clamp and 10′ of PVC tubing to both sides, and optionally the 3/8″ barb to garden hose adapter on one tube so that it’s easy to plug into hose water.
- Perform a leak test before you brew! If the compression fitting is leaking, tighten the nut 1/4′ at a time until it stops. If water is leaking where the PVC tubing is connected, tighten the hose clamps.