Wednesday, October 5, 2011

Build Day - Immersion Chiller

This one has been a ridiculously long time coming. After nearly destroying my tub and spending countless hours swirling the brewpot around and recirculating cold water, I finally got down to making an immersion chiller. This turned out to be a bit of a comedy of errors requiring several additional visits to the plumbing supply store, but in the end I got 'er done and am so far pretty happy with the results. But, first things first.

Before I could get down to making a chiller I had to decide what kind to construct. There are various high tech chillers on the market, but most homemade versions seem to fit into two categories: immersion and counter-flow. An immersion chiller is, as the name suggests, immersed in the hot wort after the boil and cold water is run through it to bring the wort down to pitching temperature. A counterflow chiller takes the hot wort itself through a pipe and has cold water around it, usually in another tube. Immersions are easier and cheaper to build, easier to clean, but not quite as efficient. Counterflows are more complex, usually requiring soldering, but can chill hot wort more quickly. Seeing as this was my first crack at making a chiller I figured I would tackle the more simple immersion chiller. The fact that wort itself is actually run through a counterflow also worries me somewhat as thorough cleaning of the inside of the tubing could be difficult.

After buying the necessary parts at a local plumbing store I headed for home, optimistic about my new chiller-to-be. The first major challenge I would face was bending the pipe until it was small enough to fit into my brew pot, which tapers to a small diameter at the top. I got the pipe bent until it fit nicely in my pot, but when it came time to bend it back up to where the water would flow out I ran into trouble. The fellow at the shop had assured me I wouldn't need a tube bender and so trusting in his advice I took a deep breath and went for the bend... and crimped the pipe. Badly. After my attempts to fix the pipe made the crimp worse beyond any hope of repair, I knew I was beaten, and the plumbing store was closed... damn.

Next day I hurried to the store on my lunch break to buy more tubing and a freakin' bender. Now I was ready, and armed with my bender I shaped the coil to perfection, and with much care, patience, and sheer brute strength managed to bend the pipe back inside itself back to the top of the coil to allow the water to flow out. At last! I was victorious! In triumph I removed the spring bender from the last section, and saw to my horror that it had crimped... inside the bender! After a long session of tears and gnashing teeth I inspected my work in disgust, but found that the crimp was relatively minor and should allow for adequate flow. Breathing a sigh of relief, I proceeded to attach the fittings and the dishwasher hose and headed outside for a test run. Man was this going to be sweet! I picked up my garden hose ready to connect it up and saw a male end. I looked at my chiller... and saw another male end. No, this couldn't be happening, could it? Well, after a solid five minutes of deep breathing I realised that yes, it had happened. The plumbing store was closed. Again, I was screwed.

Next day and another hurried lunch break I was in possession of a female connection and set for a trial run. The first run was a huge success with great flow rate and only the smallest leak out of the inlet connection at maximum pressure. After the application of a bit more teflon tape there were no leaks to be seen and the stage was set for the first use. The first batch I used it on chilled to 20 degrees C in 20 minutes, a huge improvement from 30 to 40 minutes hunched over the tub, just to get the wort under 30. I made some minor adjustments to the coil so more tubing will be submerged in the wort and I'm confident that next time I can get this down below 15 minutes. If I can hit this target I will be one happy brewer. Check in for the next build day when I will construct (or at least attempt to construct) a new and improved mash tun. See below for parts and instructions for making a sweet immersion chiller.

PS The moral of the above story is that if you do have a narrow topped brew-pot (which hardly anyone on earth does) then maybe go easy on yourself and use 3/8" copper tubing, and remember to buy the right size fittings if you go with the smaller diameter.

What You Need

(3'-10') 5/8" dishwasher hose (depending on how long you want your discharge hose to be)
(25'-50')| of 1/2" OD soft copper tubing (the longer it is, the more surface area, the faster the chill)
(2) 1/2"x1/2" compression male pipe connections (for connecting directly to the tubing)
(1) 1/2" PXF poly adapter (for connecting from the outlet compression connection to the dishwasher hose)
(1) swivel hose adapter 3/4FH x 1/2 FIP hose connection ( for connecting a male garden hose to the inlet compression connection) *Note* for female garden hose you will need a 3/4M Hose x 1/2 FIP hose connection, don't be like me, buy the right one the first time
(1) roll 12mm x 12mm teflon tape (for waterproofing all connections)
(1) rubber hose washer (essential for preventing leaks if connecting to male hose)
(1) s/s clamp 9/16" - 1-1/16" (for keeping the dish hose from leaking around the poly adapter)
(1) 1/2" spring tube bender (buy this. trust me. it costs less than two bucks and will make your life way easier, and prevent you from crimping and wrecking the expensive copper tubing... which really sucks)


Slowly and carefully bend the tubing into a coil to a size that will easily fit your brew pot. Using something to wrap it around (like a scuba tank or corny keg) makes this much easier. Remember to leave a piece at the top for the intake that can me bent at a a right angle and still be long enough to extend past the top of the brew pot. Now, VERY carefully and slowly and using your pipe bender (I really can't emphasise this enough) bend a section at the bottom back through the center of the coil and up and out of the coil. Again, leave enough to be bent and extend past the top of the pot. Bend the two ends at right angles (with the bender) and attach the two compression fittings to the two ends of pipe, using teflon tape on all the fittings and threads, including under and over the ring in the compression fitting. Connect the poly adapter to the outlet and the swivel hose adapter to the inlet. Connect the dishwasher hose to the poly adapter and secure it with the clamp, and put a washer in the hose connection if its female. That's all there is to it, give it a test run and then fire it up and cool down that wort. Happy Brewing!

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