Counterflow Wort Chiller

I built a counterflow wort chiller of the garden-hose variety, like many others out there. I mostly followed the typical pattern. I chose to use 1/2″ copper tubing fittings to make the ends, similar to other designs I’ve seen. The only interesting twist I added was an attempt to better-approximate the efficiency of the “convoluted copper” heat-exchangers like the Chillzilla or Convolutus.

And, as usual, I photographed the construction, thinking that maybe someday I’d make a web-page about it.


  • 30′ of 3/8″OD copper tubing.
  • Garden hose, with an inside-diameter that can form a tight fit on 1/2″ copper tubing. I think mine was 5/8″.
  • A long length of 14ga bare copper wire, from the electrical section. Doesn’t need to be one piece. I bought a shorter length of 6ga (TODO: check this) stranded grounding wire, and unwound the individual conductors.
  • 1/2″ copper tube fittings, “sweat” type (ie, soldered):
  • Two tee fittings.
  • Two end caps.
  • Six short pieces (about 2″) of 1/2″ copper tube.
  • Two brass male garden-hose to 5/8″ hose-barb adapters. We won’t actually use the hose-barbs, we’re going to solder them on. Make sure that a piece of 1/2″ copper tubing fits fairly snugly inside the hose-barb side of the fitting. Snugly enough that it will be water-tight when soldered.
  • Two hose clamps large enough for the 5/8″ garden hose.
  • Plumbers’ solder. Not tin/lead solder.
  • Acid paste flux.
  • Soldering Copper Tubing

    The end fittings are assembled by soldering. Learn how. It’s not that hard, and is a useful skill to have. If you’ve never soldered copper tubing, this is a great way to learn, instead of inside the cabinet under your kitchen sink. Here’s a quick lesson.

    You need a propane torch, plumbers’ solder, and acid paste flux. You need an acid brush for applying the paste flux. You need a steel wire-brush or sandpaper, for cleaning the inside and outside surfaces of the pieces to be soldered.

    Start by cleaning the mating surfaces with the wire-brush or sandpaper until they are bright and shiny. The idea is to remove surface oxide from the copper. Using the acid brush, apply acid paste to the mating surfaces, the inside of one, and the outside of the other. Push the parts together with a twisting motion. It should go in easily, and with most types of fitting the tubing will hit a stop when it’s been inserted to the correct depth (about 1/2″).

    Fire up the propane torch, and adjust to a moderate flame. Apply the flame to one side of the fitting. The acid paste will melt and possibly drip out, so make sure there is nothing important below. The hottest part of the flame is at the tip of the inner cone, try to get that part of the flame right up to the copper. After 10 or 20 seconds (or before, it doesn’t matter), you can apply the solder the opposite side of the joint. The idea is that the copper should melt the solder, not the flame. If the copper can melt the solder, then it’s hot enough to form a proper joint. If the flame melts the solder, the copper may not be hot enough for the metals to alloy together, and you’ll get a “cold” solder joint.

    In a proper joint, the solder is “wet” and flows all around. In a cold joint, the solder will be balled up, like water drops on waxed paper.

    If the copper is hot enough, the molten solder will be sucked into the joint. Apply solder until the joint seems full, it doesn’t really take very much, just about 1/2″ of solder to do a 1/2″ pipe joint. It takes a bit of practice to get just the right amount of solder. I usually overdo it, and have blobs of excess solder hanging from the bottom of the joint. It still works, it just looks ugly.

    End Fittings

    Take a copper end cap, and drill a 3/8″ hole in the end.. You want the hole to accomodate the 3/8″OD copper tubing with a snug fit. Solder the three short pieces of tubing (about 3″) into each branch of the tee fitting. Onto one of the straight-through branches of the tee, solder on a drilled end cap. Onto the right-angle branch of the tee, solder the brass 5/8″ garden-hose to hose-barb adapter. The adapter isn’t really made to be soldered like this, but I found one that was a reasonably snug fit on the 1/2″ tubing, good enough that solder could seal it.

    It should all look like this. Make two of them.

    End cap schematicCompleted end fitting

    Inner Tube

    The efficiency of counterflow heat exchangers is influenced by two things, the contact area between the hot and cold surfaces, and the ability to maintain a temperature differential between the hot wort and the cooling water. There are conflicting demands at work. Using a smaller diameter for the inner tube will make a more efficient heat-exchanger. The reason is that with a smaller diameter, a larger proportion of the hot wort is in contact with the tubing wall. But efficiency isn’t everything, we also need a decent flow-rate, or you’ll be cooling your wort all night (and that would completely defeat the purpose of a counterflow chiller.) The usual compromise most people go with is 3/8″OD copper tubing for the inner tube. I did the same.

    Maintaining a temperature-differential is the whole raison d’etre of the counterflow design. If you had the wort and coolant flowing the same direction, you’d have a very large differential at the input side, but the differential would approach zero partway along the length of the chiller. At that point, the wort is lukewarm, and so is the coolant water, and the transfer of heat will stop. The counterflow approach is better because heat transfer continues along the entire length of the chiller. In fact, with good efficiency, the cooled wort can approach the temperature of the incoming cold water, and the cooling water comes out the other end almost boiling.

    The efficiency of counterflow chillers is reduced by laminar flow and the skin effect. When liquid flows in a tube, the flow rate tends to be highest at the centre of the cross-section, but friction makes the flow slower as you move out toward the wall of the tube. The slower flow rate near the walls of the tube reduces the rate of heat-transfer. In addition, laminar flow can result in pockets where the flow-rate approaches zero, effectively eliminating heat transfer entirely in those areas.

    The very best counterflow chillers, such as the Chillzilla, overcome laminar flow and skin effect using “convoluted copper” tubing for the inner tube. This is copper tubing with a square cross-section, twisted into a spiral. The result is more turbulence in the flow, breaking up laminar flow, and keeping the temperature of wort and coolant even over the entire cross-section.

    Homebrew convoluted tubingI have no access to convoluted tubing, but I tried to approximate the idea by wrapping a spiral of copper wire around the outside of the inner tube, and securing it in place with solder. The wire is on the outer coolant side of the tubing, not the inner wort side, so I’m not worried about the effect on the beer of the solder or acid paste.

    I uncoiled the tubing first, and straightened it on my basement floor as best I could. I only soldered in one place every half foot or so. Doing this to 30′ of tubing took quite a long time. Leave the ends of the tubing clear for six inches or so, so there won’t be wire inside the end fittings.

    Don’t use too much solder here. It will form hanging blobs on the bottom side of the tube where you won’t see them, and those blobs will make the insertion of the inner tube into the garden hose a nightmare. Trust me on this. While the solder is hot, pluck the tubing like a guitar string to knock off the dangling solder blobs.


    Cable-pulling lubricantNext cut the ends off the garden hose, and reduce the length to about 30′. If your hose is long enough, cut pieces on both ends that are long enough that maybe you can make use of it for somthing else, like filling carboys. You want the hose to be shorter than the inner tubing by about the length of both end-fittings, plus a couple inches more to have the inner tubing protruding from the end caps.

    Inserting the inner tube into the garden hose is quite tricky. Try to get the inner tube as straight as you can. Try to do the same for the garden hose (good luck with that). To ease the insertion, I used a cable-pulling lubricant, the kind used by electricians to fish cables through walls. It’s basically a soapy water-based gel. Applying it liberally throughout this process will make it much easier. The lubricant is only in the coolant part of the chiller, don’t worry about its effect on your beer. When finished, you should have the inner tube protruding from each end at least a couple inches beyond the end caps.

    At this point, slide a couple hose clamps over the garden hose, one at each end. If you forget to do this, you will absolutely hate yourself later.

    Now one of the end fittings is installed. Slide it on, letting the inner tubing protrude through the hole drilled in the copper end-cap. The 1/2″ copper tubing at the other end of the fitting should go at least an inch inside the garden hose. Slide the hose-clamp over the tubing and tighten to seal. Now apply solder to seal around where the inner tubing protrudes through the end-cap.

    Chiller endChiller end solder detail

    I did not solder the the opposite end-fitting on yet, because the coiling-up operation might cause the inner tube to move relative to the outer hose. So, coiling it up is the next step. I wanted to get mine coiled up as a single orderly stack of turns, thinking that would help all the wort drain out. A random bunch of turns would trap a lot of precious beer in local low spots. I used a carboy as a form to coil it up on. Not easy to do a good job by yourself, get some help. I used a lot of nylon zip ties to hold everything together as I wound it up. Start with the already-soldered end.

    When it’s all coiled up, you can install the second end-fitting. First, make sure the hose-clamp is already on there. This end-fitting is installed just the same way as before, but be careful when soldering not to burn the nearby turns of the hose. In fact, it’s probably better to unroll it just a bit while soldering.

    Completed wort chillerAnd that’s about it.

    You have some options on what you do with the wort-in and wort-out fittings. You can just put plastic tubing directly over the copper tubing, and clamp it. Or you could install hose-barbs. They suck though, too hard to take apart again.

    I use flare-type fittings. I used a flaring tool to flare the ends of the tubing, and then installed flare-flare couplings. I have lots of hoses with flare-nut ends on them. And when the chiller is not in use, I leave it filled with weak iodophor solution, and sealed with flare caps.



    104 Responses to “Counterflow Wort Chiller”

    • Just finished mine. Thank you for the schematics, this was fun! I ended up using a 3/4″ ID contractors hose as the 5/8″ hose was too difficult to push through, even with the lube. The clamps need to be really cranked to seal the connection. Also, I haven’t been able to get the garden hose adapotors to connect. However, it is no big deal to make a length of 1/2″ tubing with a garden hose adaptor squeezed onto it and attach the tubing to the copper tube of the CFWC. I coiled it myself around a soda keg, but wish I had waited for some help. The coil is pretty good, but it could have been better. I figured that being a relatively strong guy would make it easy… ahhh, hubris… That’s about it! Can’t wait to brew a batch with it.

    • Used mine for the first time yesterday before the Extreme Beer Fest here in Boston. Holy Krausen! My hose water temp is very cold, and this chiller got my wort down to 55 degrees F in about 5-10 min. The wort was pitched onto a yeast cake from the last IIPA batch and it started vigorous fermentation within six hours. This design, with the turbulence wire, absolutely kicks serious ass. turns out that using some extra length of hose to extend the input and output of the water was a good idea, allowing for a bit more flexability in attaching and detaching. Again, THANK YOU!!!

    • To Dave,

      Your appreciation for engineers is masqueraded by your lack of trust and knowledge in/of them. I know your brother is an engineer, so I know you don’t mean insult. I, too, am an engineer. I’m a mechanical engineer, so I have plenty of education and experience with fluid dynamics, thermodynamics, and heat transfer. Your comments like the ones below are a bit short sighted.

      “They like to simplify until they reach something tractable”

      “Engineers should wear a number on their forehead that indicates what percentage of that which comes out of their calculator actually pans out ‘real world’, givens and all.”

      First of all, the “wort is infinitely viscous” assumption is way off. I don’t know who said that, but that’s just plain ridiculous. Viscosity is a measure of a fluid’s resistance to shear stress (i.e. how thick it is). Infinitely viscous is quite obviously an absurd statement. I’m not blaming you for that one; that’s to whomever said it.

      In most calculations done on this page, the “givens” aren’t actually givens in reality, right? We’ll agree on that. Certain assumptions have to be made in this case (all theoretical calculations, really). Well, in the real world, most of these “givens” you talk about are actually variables. That’s where differential equations and other tools come in handy. Things like viscosity in wort aren’t going to be constant, but if we can develop a trend or model from data about wort viscosity, then the % error is reduced to negligible or darn near it. Of course, no one here will actually collect enough data to get to that point (because let’s face it; we’d rather just brew the damn beer, right?), and the model will change depending on all the variables considered (each batch of beer will be different), so assumptions have to be made in simple calculations. These are theoretical estimates, of course, and I wouldn’t put stock in any values you see here within a 10% tolerance. These aren’t the kind of values you’d build a roller coaster with.

      • Dude, this is beer making! Not life and death! Glad to know you are smarter than the average bear!

    • Very nice thread, lots of technical bantering and some common sense thrown in as well. I am interested in designing a non-CCF chiller in the immersion style- wait, I’m not done yet! My angle is to drain a 10-12 gallon batch through perhaps 30 feet of 1/4 inch copper tubing immersed in a big bucket of ice water with an eye on replenishing the ice as it melts from the heat transfer, a “reverse-immersion” if you will. I have built and used a CCF chiller in the past with great success but the one aspect of that which always bothered me was the ammount of water that was used (wasted). My questions to all out there are:
      Will this work to satisfaction? Can I reduce the temp from 200 to 70 using this method? Is 30 feet of copper enough? Should I use 50 feet? Would the copper wire wrap trick help as an additional heat transfer mechanism or would it be so minimal as not to be worth the bother? Most importantly, is this theory even worth the brain cells devoted to the idea or am I simply off my rocker on this one? I would appreciate any and all thoughts, comments, critcisms, diatribes, and even harsh screams. Thank you.

    • From my perspective, the copper wire winding was all about inducing turbulence in the coolant, so that cold coolant is continually brought in contact with the tubing, no dead pockets.

      But in your case, unless you take steps, the coolant will be motionless. The coolant in close proximity to the copper tubing will quickly warm up to the hot wort temperature, and then heat transfer will stop. The rate of heat transfer is proportional to the temperature difference. As the coolant temperature outside the tubing approaches the wort temperature inside the tubing, the rate of heat transfer approaches zero.

      If the coolant is motionless, then the copper windings will not help induce turbulence. I would suggest that you should get the coolant moving yourself. You could use a pump to circulate the coolant, drawing from the bottom of the bucket, and returning to the top. Since it’s only coolant, not beer, the pump can be any cheapo Home Depot pump, it doesn’t have to be food-grade or magnetically-coupled or anything fancy.

      Alternatively, you could put some kind of impeller in the bucket to keep things moving.

    • I just built one of these yesterday and wanted to add a few comments. I used a 20 ft roll of copper tube, used 14 ga copper wire from scraps from building my workshop, and a 25 ft potable-water hose. Each piece of copper wire was 3-4 feet long and I reversed the wind direction, clockwise to counterclockwise, with each piece to further increase turbulence. I also used drilled out compression fittings to seal where the copper tube exits the chiller. I used lead-free solder since I intend to reclaim the hot outlet water to fill my hot liquor tank for either the next batch (I usually do two in a row) or for cleaning. I plan on testing it in service tomorrow. I will note that my dad and I had a heck of a time getting the hose over the copper – it eventually required using a fish tape and about quart of dish soap. I don’t know how anyone got 30+ feet assembled with the spiral over the tube.

      Now for the tech talk. Despite the comments above, I will admit to being a mechanical engineer (witha masters degree and professional egineering license) and a government worker. Scientists always complain about engineer’s assumptions, but without them no practical device gets built. I went through the counter flow heat exchanger calculations using the NTU method (number of transfer units) and found the calculation is quite sensitive to the assumptions (a factor of four or more). The flow inside and outside the tube is borderline turbulent (no wire, smooth concentric tubes assumed), depending on the assumed flowrates. I used 1 gpm on the hot side and 2.5 on the cold. Additionally, the Reynolds number is also considerably effected by the temperature which changes significantly along the tubes and fully turbulent can’t be assumed unless Re > 4000. I can’t calculate the effect of the wire, but in all areas (turbulence, fin, keeping tubes centered) it is in the direction of goodness, though I do think it makes inserting it into the hose more difficult.

      I suspect 1 gpm is too high for a gravity system (I have a pump); kettle-to-carboy is not more than a few feet of hieght drop and 20+ feet of 1/4″ ID tubing has a significant frictional effect that cannot be ignored. A decent thumbrule (for cold water) would be about 0.2-0.7 psi pressure loss per foot when flowing at 1 gpm in 1/4 ID line (depending on material and smoothness). Using the low end of the range and 20 ft of tubing would require 4 psi, which would require over 9 feet to get 1 gpm.

      Anyway, engineering calculations regarding fluid flow and heat transfer are usually crude and must be validated with empirical data.

      Also, regarding Mike’s question above: Yes it will work, however. . .

      You will hve to melt almost a pound of ice for each pound of wort (about 8 lbs per gallon) to keep the ice bath at 32F. You might be able to use a little less if you let the water bath (melted ice) increase in temperature at the end. Tube length could be almost any length you want depending on how fast the flow is (faster flow, longer tube) and how much you stir the ice bath. A CFC will use 2-3 times more water, but no electricity is wasted freezing the ice.

      I’d considered putting a small “immersion” chiller (in a bucket full of ice) in line with my CFC water inlet to drop the temperature to improve cooling. However, that adds complexity to my setp and the same cooling effect could be achieved by reducing the flowrate of the wort (my inlet water never gets above 60F).

      As a side note, I had been using an immersion chiller which worked pretty well, but decided to go with a CFC to save the 25-45 minutes of chill time (10-12 gal) since chilling and racking will now be simultanious. With the IC, I found a great improvement by doing a few things: 1) make sure the coils are at the top of the wort level, 2) mist/spray water on the outside of the kettle, and 3) stir the wort occasionally using the immersion coils. I intend to continue to spray down the kettle when I use my CFC.


    • I finally used mine yesterday. It worked great. I could get a little over 1 gpm flow through the 20 ft chiller, about 7 feet of hose, and my tube areator. I could throttle my 50 psi water flow down and still maintain the wort outlet between 65-75F with 59F inlet water temp. I have to refine my technique to reuse the hot outlet water to refill my hot liquor tank (HLT). I tried on my second batch, but I had the wort throttle down to about 0.5 gpm and the water flow pretty high – that put about 80F water in my HLT. I had to throttle the wort flow because the high flow makes my areating tube go crazy and my bucket was overflowing with foam by 2.5-3 gallons.

    • Thanks for the awesome plans, I’m shortly about to build my own. This topic brings to mind the similar principles in water cooling a PC when over-clocking. I’m thinking of applying some of these principles into my design, ie a radiater/fan, reservoir and pump, albeit on a slightly larger scale. Water turbulance appears to be a key factor in good pc water cooling sytems and I see no reason why turbulence in this application wouldn’t be the same.

    • Thought i’d better explain my reasonings better, I’m thinking of applying some of these principles into my design, ie a radiater/fan, reservoir and pump, albeit on a slightly larger scale, In Australia we have water restrictions so the above would cool and recycle the water (or so my thoughts go)

    • Does it matter which way the cooling water enters. Going to build one today and try it out this weekend. Just not sure if the cold water should go into the end where the wort comes out or where it goes in?

    • Oh, it matters. The key concept in a counterflow chiller is counterflow… meaning the flows are in opposite directions.

      The rate of heat transfer from the wort to the coolant is proportional to the temperature difference between them. If the there is no temperature difference between coolant and wort, then there will be no heat transfer.

      Suppose that the wort and coolant are flowing in the same direction. There will be a great deal of heat transfer at first because the wort would be very hot and the coolant very cool. But after traveling along together for a short while, they would reach an equilibrium, wort and coolant at the same temperature… the average temperature. No matter how long the chiller was, you’d never get the wort any cooler, or the coolant any hotter. They would emerge together at the far end both luke-warm.

      Conversely, suppose they’re flowing in opposite directions. In that case, the coolant near the end of its travel is encountering incoming wort at very high temperature. And the wort at the end of its travel is encountering incoming coolant at very low temperature. So, even at the ends of the chiller, there is still going to be some heat transfer going on. As the length of the chiller approaches infinity, the heat exchange asymptotically approaches 100%. At infinity, the wort temperature out exactly equals the coolant temperature in, and vice versa.

      In practice, you can get very close to 100% heat exchange with a practical chiller length. I get wort coming out that is cold, and coolant coming out steaming hot. I get one hell of a cold-break too. My chiller is, I think, rather longer than it needs to be, which costs me in flow-rate. It takes a fairly long time to drain my kettle into the fermenter.

      But it does need to be counterflow, or the whole thing is shot.

    • Wow, three year old blog and still getting attention. Very nice.

      Love the design, and wondering if anyone followed Luke A’s design change of using a 1/4″ inner tube? If it’s sufficient, it should be a lot easier to get through the garden hose!

    • I haven’t seen 1/4″ soft copper in my neck of the woods, but yes it would be easier. Using a similar design, the only difficult part was the Cu tube insertion, more specifically the last 5 feet of it. Turns out the not so smooth Cu end was peeling a thin layer off the inside of the garden hose. Great arm workout, that was. However, the finished piece was very functional, cooling 5 gal 95 deg C wort to 18 deg C in about 15 minutes, using 10 deg C input coolant (didn’t measure flow rate).
      Starting one of these without a pump or ball valve on one’s kettle is tricky. I ended up priming the sanitized chiller with hot water, clipping closed the outlet to the fermenter and then putting my copper racking cane attached to the chiller into the wort. Unclip at the fermenter gave enough suction to start what turned out to be an efficient siphon. Sucking on the outlet hose just ain’t enough!

    • @piper – The ‘coolant’ is cold water which runs from a tap, through the garden house. It isn’t motionless, so I’m not sure I understand what you mean?

    • Scott F – Thanks for doing the calcs and putting ranges on the assumptions. (ME geekness and 3 yrs valid post proves the engineering effort was worth it ;-) OK, after reading this posting 2 yrs ago and 10yrs using an immersion coil, and enough procrastination, I’ve decided to take the plunge and cut chill time, rack and aerate in one go and build a CFC.
      Also, I’ve read in other blogs that a slick type inner plastic in the hose seriously eases inserting the copper tubing, especially with a turbulence-inducing wire spiraled around the tube. I like Piper’s idea of switching the wire’s spiral direction. I’ll try that optimization. Thanks!

    • Charlie Barleycorn

      I built one of these chillers about 18 years ago and still use the same piece of equipment to this day. The only real dif is that the fittings I used where the copper tubing exits and enters the 1/2 inch fitting are reduction fittings instead of drilling holes through the copper cap end fitting. The reduction fitting lets you go from the 1/2 inch fitting down to something like 1/4 inch which gives you a nice collar to solder to. Seems to me to be better than the thin surface in this example. I don’t recall the size of copper tubing I used, but it fit the reduction fitting snugly- probably 1/4″ O.D. My chiller has allowed me to go from boiling hot down to a pitchable temp in less than 1/2 hour on a 5 gallon batch. I love my old faithful chiller!

    • I wonder if anyone would care to speculate the effect a small diameter wire, say 20 GA, wound in a fast pitch of about 1 rev/inch for six inches or so, then skipping a foot or more and reversing the direction would have on the laminar flow and skin effect.

      I am envisioning the turbulence reducing slowly over the non-wound length. I also believe a small gauge wire would cause almost as much turbulence as a large wire, and would be much easier to thread through the garden hose.

      Your theories?

    • I’m planning on building this here pretty soon. I don’t own a pump yet and was wondering if gravity will work for pushing the wort through the chiller? I’ll get a pump eventually, but was wondering if I could just make due for now.

    • Yes, gravity works fine. I think that’s how most people operate them.

      I position mine so the coils are laying flat, with the hot wort entering at the top of the downward spiral. The hope is that all of the wort will run out and not leave any trapped in low spots.

      This does create a problem with those so called “three-level” brewing systems that count the ground as the bottom level, and put the boiling kettle there. You have no more “down” left when it comes time to move the wort through the chiller and into the fermenter.

    • In place of the 3/8″ copper inside the hose ..Can I use a beer line as it is much cheaper than the copper where I live

    • Copper is expensive where I live ..Can I use a length of beer line inside the hose

      • Copper is a very good thermal conductor, almost the best. Beer line is a thermal insulator. I think you would get very poor performance using beer line in place of the copper.

    • I’v been using my home built chiller for 15 years now. Unlike yours, I used 25′ of 3/8″ soft copper for the wort (inside) line and 20′ of 3/4″ soft copper for the water jacket and 3/4×3/4×3/8 reducing tee’s I slightly crimped the 3/8″ copper diagnaly every foot before inserting it into the jacket to create turbulence

    • Thanks for the info!!! I just finished mine, this thing kicks serious ass!!! I let 209 degrees wort run through it for about a minute to sanitize it then I turn the water on and it drops the temp of the wort coming out from 190 degree F to 63 degrees F instantly! I only made mine 20 ft long and ended up using steel fish tape to pull the copper wire through the garden hose!. Incredible how well it works!!!! Thanks again!

    • This is great thanks, this is exactly what I was looking for!

      I’d like to point out that it may be a bit easier to use a 1/2″ to 3/8 reducer on the end cap instead of doing any drilling. It will not only make it easier to solder that bit of the design, but last longer as well.

      Also it would be helpful to borrow a spring pipe bender to avoid kinking up your tube.

      • The reducer would be great, except they usually have some kind of depth stop that prevents the 3/8″ tubing from passing straight through. Sometimes the depth stop can be drilled out or otherwise defeated.

        • Yup, and that’s where I’m stuck for the moment…:-p
          Drilling out a cap doesn’t sound so troublesome now… :-]


      Like many others, I found that feeding that 3/8 copper tub was hard (almost impossible) without some kind of lube. I had maybe 12 feed of tub in and could not go any further (no lube). Since my hose was a lot longer, I fitted the other end w/ a barbed hose adapter (since I’d already cut the connector off. I hooked it to the hot water heater outlet in my garage and pushed water through it. Wouldn’t you know! While running the water (counterflow direction) I was able to easily push the copper the rest of the way.

      Also, I skipped the step where you wrapped the copper wire around your tube. I tested mine out last night w/ 200 degree water and it still did an amazing job. Perfect in fact.


    • I built the chiller using 30 feet of 3/8″ copper tubing with the wire wrap. Took about an hour and a half.
      I tried it out today on an all grain boil.
      Cooled the 5 gallons of wort from the boiler at flame-out to 68 degrees in ONE pass using 49 degree water from my garden hose.
      Took about 9 minutes. Wow !!!
      I used to let separate the wort into two pots and let them sit in the snow for 2-3 hours before they would cool to pitching temp.
      Thank you !!!

    • Just wondering if you gave any thought to using the ends of the hose you just cut off and a couple more hose clamps in place of the 5/8 barb to hose fitting? You could use the female end on the water in side and the male end on the water out side so it would connect properly to supply and disposal hoses/taps.

      • I think many similar chillers do exactly that.

        It would have been hard to make it work on mine, because my hose had some kind of splines on the inside wall, running the whole length of the hose. It would be difficult to get it to seal.

        • Those splines are on kink-resistant garden hoses. They are supposed to stiffen up the inner material and let water through even if the hose is bent over on itself.

          Best to go with the cheap-o hoses, they will be less likely to have splines. Of course, stay away from anything that advertises kink resistance!

          I just finished making up a 25′ chiller. I don’t have easy access to soldering equipment so I used a 3/8 compression to 5/8 pipe thread adapter on either end with the stops drilled. Works great so far – no muss, no fuss.

    • Thank so much for the effort you put into posting this online for us.
      I just finished it and here are the minor differences…
      I went with 20 feet.
      I used the hot water lubrication method listed earlier, worked really well.
      I used the ends of the hose that I’d cut off instead of soldering on connectors. I left enough hose to make it to my sink from the stove, so I can connect and drain with the hose on the chiller.
      Just ran a test and cooled 5 gallons of boiling water down to 61 in less than 5 minutes. Man does this thing work!
      Thanks again!!

    • Very creative. Seems it would be a little bit time consuming and still cost almost the same as a plate heat exchanger for a beer wort chiller though. The problem is tube in shell heat exchangers aren’t as good either, and there’s a lot more pressure loss going through all of that hose, so less heat transfer too.

    • I want to thank you all for the info passed along on this thread over the last couple of years. I’ve been holding off making one but with all the info here I’m ready to go ahead with it. Thank you everyone. Let you all know how it goes.

    • Built the chiller last week. 3/8 in. tubing and 3/4 in. hose and fittings. Tried out sat. morning with just boiling water went from 210* to 70* in 5 sec. Drained 6 1/2 gal. in 15 min. Totally awsome. Wrapped the coil around my tower below the boil kettle and above the fermenter, and just use gravity to drain. Thank you for posting the plans.

    • Father Barleywine

      Made a variant of this bad boy today, planning on using it tomorrow in place of my old counterflow on a 1/2 barrel batch. I used 3/8″ ID 1/2″ OD soft copper pipe, and 3/4″ copper T and 3/4″ straight pipe for two legs coming off the T. 3/4″ ID (kinda) garden hose was attached to these legs for the counterflow and for connection to inlet and outlet hoses (rather than a brass hose connector). On the third leg, I used 3/4″ straight pipe, a 3/4″ to 1/2″ copper adaptor, 1/2″ straight pipe, and a 1/2″ to 3/8″ adaptor, all soldered together in a row. I still find the ID/OD switcharoo confusing, as a 3/4″ to 1/2″ adaptor connects 3/4″ and 1/2″ straight pipes, but is too big for a 1/2″ soft pipe . . . for that you need a further 1/2″ to 3/8″ adaptor. I had to ream out the interior of the 3/8″ side of the adaptor a bit with a 3/8″ drill (which, of course, is smaller than the 1/2″ diameter of the 3/8″ side of the adaptor) so I could slide the whole thing over the 3/8″ ID soft pipe without it locking up, but using the adaptors you get >1/4″ of sleeve to solder over the tube, which is more dependable with my knockabout brewing style. Finally, I attached a 1/2″ ID vinyl food grade to the outlet end, and a 1/2″ compression fitting to 3/8″ MIP threaded that allowed me to attach my pump, which has those braided stainless tubes with 3/8″ female ends.

      I skipped using the 3/8″ OD pipe because 1) I would have had to use a further adaptor and more straight pipe, and people would have laughed, and 2) Lowes only had 10′ coils of the 3/8″. I think the 20″ 1/2″ OD pipe will work nicely, even without soldering on wires around the outside, as I believe the larger gap between pipe and hose you get using 3/4″ ID hose and 1/2″ OD pipe along with the variation in this gap due to coiling the whole thing will lead to plenty of flow turbulence. I pump my wort with a little magnetic pump, and my boiler is raised so I have good velocity . . . I’ll let y’all know if I get good enough cooling. I think the greater counterflow velocity of the cooling water with the larger hose will overcome any issues with not having sofisticated turbulators in the mix.

      Here’s a pricelist (Lowes, Columbus, OH) for those aspiring to repeat my performance:
      3/8″ ID 1/2″ OD soft copper pipe, 20 ft — $25.11
      3/4″ x 24″ hard pipe — $9.27
      1/2″ x 24″ hard pipe — $5.63
      3/4″ to 1/2″ coupling (2 x $2.61) —$5.22
      1/2″ to 3/8″ coupling (2 x $1.48) — $2.96
      3/4″ copper T (2 x $2.71) — $5.42
      #12 pipe clamps (2/pkg, 2 x $1.74) —$3.48
      1/2″ compression to 3/8″ MIP — $4.36
      TOTAL: $61.45
      I already had an old 3/4″ ID hose, the new ones are about $45 as all the cheap hose is 5/8″. If you go all-new, it’ll come out to about $100, but I just priced a simple immersion chiller at a local homebrew supply and it was $66. The price of copper nowadays is simply outrageous.

    • I really like your tutorial. You just don’t come across a Gem like this too often. I even linked your tutorial in my blog. (I hope you don’t mind).

    • Just gathered parts needed to construct my first counterflow chiller. Can’t wait to get to it. Brew day Next Saturday!!!!

    • Just finishing up my build after stalling out a few months ago. I couldn’t get the wrapped 3/8″ copper through the hose for the life of me when it was cold out. Used as much soapy water as I could and it still wouldn’t go. Those hoses really don’t like to unwind on their own so I left it to sit in the sun for the afternoon. Softening the hose up easily did the trick without any more lube. I’d suggest letting the hose soften in the sun for a few hours, or in a pinch, toss it in the oven at the lowest setting for a few minutes. It slid right through after that!

    • Great post. I made this a couple weeks back and it works great. Surprisingly, the easiest part was getting the wrapped copper into the garden hose. Took all of 30 seconds moving across the yard with it. Going to make on inline thermometer for it next so I know how to control the flow.

    • Thanks for the awesome plans, I’m shortly about to build my own. This topic brings to mind the similar principles in water cooling a PC when over-clocking. Really nice idea.

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