Monday, November 7, 2011

Homebrew DIY: Building An Immersion Wort Chiller

One of the great things about homebrewing is all the many skill-sets you can put to work. Because there are so many variables, brewing gives the opportunity to be infinitely creative, but it also appeals to rigid traditionalists and control-freak perfectionists as well. It can engage and enhance your knowledge of chemistry, biology, and other general Science Stuff. Grow your ingredients, or just learn more about them, and you'll find plenty to occupy your Green Thumb and botanical curiosities. So on and so on — it is the greatest, most all-encompassing of hobbies.

Then there are a few more skills and interests that almost every homebrewer is bound to brush up against eventually, if they want to make their brewing day easier. It's a DIY hobby to begin with, so why not tackle projects like building your own wort chiller?

I won't get into the "why" of wort chilling. I'll assume you already know about that, if you're building one. Cooling down your wort from boiling temp to room temp is one of the most tedious, frustrating steps in the brewing process, and there's nothing really exciting or rewarding about it — the way there is in making a yeast starter, or even bottling two cases of beer yourself. A wort chiller makes life easier, and has the added benefit of being Important Outlandish Equipment-looking. It's guaranteed to impress your friends, family and dates. "You built that yourself?" they will almost certainly say, with a certain look in their eyes.

There aren't a lot of pieces involved — a few of those clamp things for the hosing, whatever sort of connectors will allow you to connect to your sink or garden hose (obviously depends on your own set-up), the copper tubing itself, and some copper benders. The copper is obviously the most important component of this project — copper is an excellent heat conductor, and it will be doing the actual cooling by jetting cold water from your sink through its coils. It's also a bit expensive right now, but you have a few options. If you want to save some money and have a somewhat less efficient cooler, you can opt for a 20-foot coil. This will still be plenty-good at cooling smaller boils, if you're doing extract batches or half batches, for instance. If you have more wort to cool, 50 feet might be good. I opted for 50 feet, which while somewhat expensive, is still half the price of a pre-made wort chiller of comparable size. Then you have to decide what thickness to get. I went for 3/8-inch outer diameter. 1/4-inch is cheaper and works fine, but doesn't allow as much flow; 1/2 inch will be much more expensive and bulky, but will allow a ton of water to pass through quickly, which might be good if you're cooling with a garden hose outside or something. You can find copper at Lowes or Home Depot, and probably your local hardware store, in the plumbing section. It's sold as refrigeration coil, I believe.

Conveniently, the copper comes somewhat pre-coiled, but you'll still need something to shape it around. This was kind of tricky for me, as I don't have a whole toolshed of random cylindrical objects at my disposal. I've seen various guides on building a wort chiller where the instructor suggests using a keg to shape the coil. Who are these people that have a kegging setup before ever building a wort chiller? Priorities, guys, priorities. Now, I have an unusually large and fat boil kettle, so I ended up shaping my copper around a bucket. This is not ideal, and I would definitely suggest something thinner. My good friend Matt, a more clever man than I, shaped his around the inside of his kettle. I'll probably reshape mine later, if I can, but it does the trick for now.

I mentioned that you'll want a copper tube bender above. It's basically a sturdy metal slinky (seen in the right-side photo above, four 'coils' from the bottom) that fits snug around the copper and prevents you from kinking it by bending too hard. I was lucky enough to borrow one from aforementioned friend Matt; he is truly an All-American Hero. It should be rather difficult to kink the center parts of the coil, anyway; it'll be easiest when you're doing the sharp bends of the in/out tube.

Here it is, all bent into shape and sexy looking. Makes sure the 'ends' are bent slightly downward, so that if any wort seeps through the connection, it'll trickle down the hose and not into your wort. The rest is easy; attach hose to each end; secure with a hose clamp. Make sure the "out" hose is something that will stand up to high temperatures, since it will be spewing extremely hot water for the first few minutes.

Because of the size of my chiller, it does kind of "slinky" down when I pick it up. I've seen various solutions to this, but it doesn't bother me much; just be careful when dropping it into the wort. A few guides online show people soldering their copper together so it retains its shape, but this probably isn't a good idea. Solder is composed of mostly tin and/or lead. You really don't want these leeching into your wort.

My greatest difficulty was figuring out how to hook the hosing up to a faucet in my tiny Brooklyn apartment. My kitchen sink has a weird spray-head faucet that I couldn't — and still can't — figure out how to detach for the life of me. Eventually I realized my bathroom sink would work — the aerator, the little cylinder under the faucet head through which the water actually passes, just screws out. I bought a makeshift adapter thing that screws in; it mostly fits, kind of leaks, but it's good enough for now. I wish I didn't have to bring my wort into the bathroom; hopefully you will have a better setup.

Drop the chiller into the boiling wort 15 minutes before the end of the boil in order to sanitize it. Then, put it to work. Feel proud. And may god help you. There is no turning back now. You will forever be known to your friends as "that guy who spends all his money on and cares way too much about beer." You will be a burden to your housemates and/or Significant Other. Your addiction to homebrewing is now irreversible.

If you enjoyed this construction project, perhaps consider building your own stir plate next.


  1. Ha... I got a kegging setup before getting a chiller... woops! But I'm making one today :)

  2. Awesome article! Ive noticed the more I brew, the more I'm thinking about how to perfect it. Thanks for the tips, and great pics!

  3. If you brew outside, buy the copper, two clamps, and a washing machine hose. Cut the hose in half and you have two ready made ends that will connect to your garden hose. You could even attach the outlet to a sprinkler and water your garden while you cool your wort. Double duty!

  4. Awesome and perfect tips! I will definitely try this creative idea at home!

  5. Cool hack. I didn't think you could actually have a homemade wort chiller just by buying stuff from the local utility and appliance stores.

  6. Smart move! You can actually have two cases of beer from this one huh? Kudos to you, sir, for sharing this one, it feels easier now that there are stores nearby where I can get tools to test homebrewing.

  7. I made a wort chiller a while back using three strands of thin (1/4 inch) tubing, so it chills much faster- much higher surface area to chill fluid volume ratio. My write-up is here:

  8. A few guides online show people soldering their copper together so it retains its shape, but this probably isn't a good idea.


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