How to Power and Install a Coolworks Ice Probe on a Conical Homebrewing Fermenter.
Updated 03/08/07

All power supply information was learned from PC Power Supply. This is an outstanding site, loaded with all the info you'll ever need - and then some. I read the information on the PC Power Supply web site, followed the instructions and it worked well for me.

Please don't contact me about wiring or converting your power supply, as the little I know came from the PC Power Supply web site. I am happy to help try to answer any other non-power supply related questions though, so please feel free to e-mail me at:

Working with electricity and PC power supplies can be dangerous. You can get electrocuted!!! Working with electricity while drinking homebrew is a BAD idea (don't ask me how I know that)! Lastly, Ice Probes create an invisible thermal-electric plasma stream from their tip. Be careful where you aim it. Ideally, the Ice Probe's tip should be pointed so the plasma stream reflects off an interior wall of the conical. Gotcha! Now that I have your attention again, seriously, just be careful and you'll have no problems. This is actually a very fun and easy project!

Prosit from Milwaukee!

Tom Bardenwerper

Return to Cedar Creek Brewing Company

Click on images for larger picture.

Parts (top row, left to right):

  • 350 Watt ATX PC power supply - output: 12v, 10amp.
  • Coolworks Ice Probe
  • Duct tape and foil tape (for insulating with aluminum bubble insulation - R factor 8)
  • Center bit for hole saw
  • Bi-metal hole saw
  • Male/female wire plugs
  • Heat sink compound
  • Wire ties

(03/08/07 - The image above also shows a Wirewound Resistor and heat sink compound. Since I first constructed this project, I have learned the resistor and heat sink compound is not needed.)

Open power supply, cut off all wires from main wire bundle EXCEPT for one peripheral power wire set. BE VERY CAREFUL AROUND BIG CAPACITORS!!!
(large cylindrical tube-like things)
They can give you quite a shock if you cross one! It is best if you let them discharge naturally by letting the power supply sit unplugged for several minutes before opening it.

Remaining UNCUT peripheral power wire set.

03/08/07 - Cut the connector off the peripheral power wire set and trim off one BLACK and the one RED wire to the same stub-length as all the other wires you cut from the main wire bundle - these two wires will not be used. Strip the ends of all wires from both the Ice Probe and two remaining power wires: the one YELLOW and the one BLACK wire from the peripheral power wire set.

Cut and strip both ends of two 4' long extension wires and connect one of these extensions to the 12v YELLOW wire and one to the BLACK ground wire, from the peripheral power wire set.

Solder the connections together.

Wrap the connections with electrical tape.

Connect the two red wires from the Ice probe together. Connect the two black wires from the ice probe together.
Mount each set in the male end of the plug. Next, mount each end of the extension wires into the female end of the plug. BE SURE when plugged together that the red (positive) wires are plugged into the extension connected to the 12v YELLOW wire from the peripheral power wire set. The black wires should then be connected to the black ground wire from the peripheral power wire set.

Plugs connected.

If using an ATX style power supply (only), find the one GREEN wire in the main wire bundle and connect it to any one of the BLACK ground wires inside the power supply. Solder the connection and wrap it with electrical tape. This duplicates a computer's front power switch and is needed in order to actually to turn the power supply on. Without this connection, an ATX power supply WILL NOT turn on!

Wrap electrical tape around the cut off ends of the main wire bundle.

Screw the cover back on the power supply. Plug it in and test out your new cooling unit. If all goes well, your Ice Probe should be running and feel cold to the touch! Now, on to mounting the Ice Probe on the conical.

I mounted my first Ice Probe (I may add a second one later, if/when I begin to use the conical to its full 15g capacity) so its probe is about thee inches below where five gallons of wort sits in the fermenter. Since cold sinks, I want the Ice Probe towards the top of the wort column where it is cooling the warmest portion of the wort. In theory, this placement should set up an efficient thermal "cycle" with cold wort constantly settling lower, pushing warmer wort up, forming a cycle. I filled my conical with five gallons of water to determine the correct level for placing the Ice Probe.

, the probe itself will be angled UP inside the conical, so you need to mount it low enough so the entire probe is submerged by at least an inch of wort/beer, when the conical is filled to its LOWEST point before kegging/bottling (such as after the very last trub dump or yeast harvest).

Mark your spot with magic marker and then tap in an indent EXACTLY where you want the center of the hole so the drill bit does not slip around when drilling.

1 1/4" bi-metal hole saw attached to hand drill.

Drilling the hole. Both the hole area and the bit are generously oiled. Apply slow pressure, hold the drill and conical VERY steady and use a slow speed while drilling. Some smoking oil is normal, but you don't want to overheat the bit, so DRILL SLOWLY!

Freshly cut hole into SS. No worries!

File both the inside and outer edges smooth to remove the burr.
CAREFUL - those edges are SHARP!
Last Step! Mount the Ice Probe on the conical. The Ice Probe's silicone gasket goes on the outside to form a water tight seal. Only the nut goes on the inside. Hand tighten the nut as tight as you can get it (unless you have vise grips for fingers - then not too tight). This should be as tight as you'll ever need for a water tight seal and will allow you to remove the Ice Probe without using tools that could gouge or scratch the nut and create a harbor for bacteria inside the conical.

You're done!
Test it out with water to learn what temperature differential you will be able to achieve. Run it for a good 24 hours and see if the temperature remains stable. For temperature drops of more than about 10 degrees below room temp, you will need to insulate your fermenter. Since I'm only fermenting ales in my conical, so far I don't seem to need to insulate my unit to hold a steady 68 degrees of actively fermenting wort in a 78 degree room. Your results will probably differ somewhat.

Conical with Ice Probe installed on left side.

Close-up of mounted Ice Probe. The edge of the silicone gasket does not squeeze down around the round cone of my conical. However, most of the INNER area of the gasket IS squeezed down very tight, so it's water tight none the less. (Replacement gaskets would be nice to have on hand for future years of use.)

Converted PC power supply resting on stand beneath conical.

The full monty - just chillin' man!

The result - a stable 68 degrees while actively fermenting
a fresh batch of ale in a 78 degree room.
Completely finished fermenter with a Ranco digital temperature controller.
Since this photo was taken, I have wrapped the entire conical (including two layers on the lid) in foil bubble-wrap insulation (~R15) and it can now maintain a 15 degree drop below ambient room temperature during active fermentation of a ten gallon batch of homebrew.