I finally got around to building a copper immersion chiller (IC). If you don’t already know what an IC is for, then it’s one method that brewers use to rapidly chill their boiled wort to 20C or the desired temperature for pitching yeast. Give or take a couple of brews where I borrowed HopZine Rob’s IC (built by @pdtnc), I have used the basic method of crash cooling i.e. put your bucket of near-boiling wort in a sink of water, adding ice to the sink when I had it, emptying and refilling the sink when it heated up. I can tell you that this is an absolute pain and a very time-consuming process, not to mention the increased risk of wild yeasts taking hold, or unwanted bacteria, bugs etc ruining your handiwork before your wort is safely tucked up and covered in a protective yeast krausen. Using an IC reduced the time needed for cooling 23 litres of wort from 5-6 hours to around 40 minutes.
I read around the subject a little and there are a number of variations on the theme of coiled copper piping. Having had the chance to see one first-hand I knew what I was aiming for, but wanted to be sure before cutting/soldering anything as the materials are quite expensive. The suggested materials and tools below might differ depending on your design:
- 10mm x 10 metres copper tubing (Hamilton Gas Products) £30.90 incl delivery. Don’t pay more than £3/m.
- 15mm x 1 metre copper pipe (I had this already but it costs about £9/m).
- 15mm copper elbow x 6
- 15mm to 10mm copper reducer x 2 (cost of copper fittings came to £6)
- Total cost of materials for my build £36.90
- Total cost of materials if you don’t have any of the above £45.90
- Blow torch (borrow one to limit costs, but cost around £15)
- Lead free solder wire (you only need 20cm or so, £17.99 for reel!!!)
- Flux (already had this, but £6-10 for a tub)
- Pipe cutter 15mm (borrowed, but approx £10 to buy)
- Tape measure
- Wire wool
- Total cost of tools for my build £17.99
- Total cost of materials if you don’t have any of the above £50.99
No point in writing too much about the method as it is fairly self explanatory from the pictures.
Step 1: Form the 10mm copper tube around a cylinder, something that suits the dimensions of your boiler. I used a cornie keg. The tube was soft enough to form by hand.
Step 2: I measured and cut the lengths of straight 15mm copper pipe that I would need to make the down pipes and the inlet & outlet. I opted to use copper elbows to achieve the angles over the edge of the boiler and to direct the water inlet/outlet well away from the stock pot. This will help prevent cooling water finding its way into your precious wort. I then loosely fit the whole thing together to make sure all my measurements were right before soldering.
Step 3: I prepared all the connecting pipes by rubbing them down with wire wool and using the file to remove any burs. After remembering to apply flux to the connecting pipes, I soldered the down pipes first by attaching the 15mm copper elbows and 15-10mm reducers, letting them cool at each stage before attaching them to the formed 10mm copper tube.
Note: the straight copper pipe you can see in the bottom of the boiler is the Hop Stopper and not part of the IC build.
In terms of what it costs to build, I managed it for £54.89, but I did borrow the expensive tools and already had a few of the materials needed. It was looking like I was going to build it for under £40 until I had to buy the solder wire. You can buy a ready made IC from brewuk for £57.50+ postage. While cost is always a factor when deciding how to put your brewkit together, I also see value in building my own where possible (and safety permitting e.g. electrics). Having said that, if you have none of the tools and materials it will cost you in excess of £90, in which case you could buy a rather nice one from The Malt Miller for £84+ delivery
My next project is to build a temperature controlled HLT and fit an element to my stock pot.