Drew's Counterflow Wort Chiller Design

by Drew Lynch, drew@webnexus.com

Parts list:

Tools Needed:

  1. Cut off each end of the garden hose, leaving about 8" attached to each "hose end"
  2. Insert the 6 pieces of copper pipe into the 6 ends of the 2 copper tees, and solder in place.
  3. Drill a 1/8" hole in the end of each copper end cap.
  4. Enlarge these holes to 3/8"
  5. attach one end cap to each enlarged "T" so that you can look through the "T" and see light through the 3/8" hole in the end cap.
  6. straighten the 50' of copper tubing, and feed through the garden hose.
  7. slip a hose clamp over each end of the garden hose.
  8. slip the copper "T" assembly over the end of the copper tubing, and into the garden hose. Attach with clamp.
  9. Solder the copper tubing to the "T" assembly where it passes through the hole in the end cap.
  10. Using the 2 remaining hose clamps, attach the hose end remnants to the "other" end of the "T" assembly.
           copper T   ______________________________________  copper T
      end+-----------+ clamp       Garden Hose        clamp +-----------+end
      cap+--+     +--+______________________________________+--+     +--+cap
            |     |                                            |     |
            +     +                                            +     +
           | clamp |                                          | clamp |
           |       |                                          |       |
          Hose end in                                        Hose end out
  11. Coil this using your favorite round object as a form. I used my old 5 gallon brewpot. Zip tie the coils together.
I attached 3/8" id plastic tubing to each end of the chiller. For the "in" end, I attached a 3/8" od copper racking cane. I hose clamped a copper Chore Boy scrubber to the end of the racking cane, to filter out hop particles.

To sanitize, I siphon iodophor solution through the chiller into the carboy. To start the siphon, put a female garden hose to 3/8" hose barb fitting on the "out" end and attach it to a water source, Place the "racking cane" into a bucket filled with sanitizer. Then run the water until all the air is removed from the system, disconnect the water source, and place the "out end" lower than the "in end" immersed in sanitizer. I use this same method to start the siphon from the hot wort (remember not to blow bubbles into the hot wort though).

This design works very well. I was able to drop boiling wort to within 5 degrees F of the tap water temperature. I found three drawbacks: 1) The flow is very slow. It took about 20 minutes to siphon 5 gallons through the system. 2) a fair amount of wort is left in the tubing then the siphon quits. 3) a fair amount of wort is left amongst the hops in the bottom of the brew kettle. I have a small food grade pump which I may attach to the outflow of the chiller next time I use it, which should solve #1 & #2 and help #3.

I may also add another, bare copper coil between the outflow of the CF chiller and the carboy. This coil will be immersed in a small ice bucket. This will minimize the amount of ice needed, and get that final, desireable drop in temperature.

Andrew Lynch, drew@webnexus.com