By the time this story arrives in your mailbox, I’ll be gearing up for the annual Oktoberfest party thrown by a local homebrew group. I hope my Fest Brew will capture an honorable mention or better, but I also plan to impress the heck out of everyone with the latest BYO project, a homemade jockey box.
   
What’s a jockey box? Ever had beer at a picnic or sporting event that poured out of a picnic cooler with tap handles mounted on it? Inside was a coil of stainless-steel tubing immersed in ice water. That coil exchanges heat in the beer for the cool of the 32° F ice water. Given a sufficient length of tube, you can deliver 40° F beer when the keg is at room temperature. So a jockey box — also called a draft box — is an ice chest with a heat exchanger, taps and beer inlet.
   
Coils can be made of stainless steel or copper. Copper is easy to find, easy to work with and inexpensive. Stainless-steel tube is none of those, but is preferred because it will not contribute metallic off-flavors to your beer and can be thoroughly cleaned with industrial-strength solutions. Copper, a “soft” metal, requires milder cleaners.
   
For our project we’ll construct a double-tap version built with copper tube. If you choose, you also can make this jockey box from prebent stainless coils. Whether you use copper or stainless, the same construction steps apply.
   
Several homebrew suppliers offer premade stainless coils in 50- to 100-foot lengths. While it seems high, the price ($75 and up) is reasonable when you consider the raw cost of stainless, which runs about 80 cents per foot). Forming a coil may be cheap, but turning corners so the ends are where you need them is not.
   
When planning your jockey box, you’ll need to consider a problem that anyone familiar with beer has experienced: too much foam when the tap is opened.     Foam is the result of gas coming out of your beer when pressure changes from high to low. As beer leaves the bottle or exits a beer tap, the gas tries to escape the liquid and is trapped by protein molecules. Some foam is good, but when too much gas tries to equilibrate, there’s too much.
   
Now that I’m kegging, I’ve been wondering how to stop the problem. My bottle-conditioned beers never had too much foam, so why does my kegged beer gush? The answer is contained in one word: resistance, a subject covered in detail at www.morebeer.com in the  “Frequently Asked Questions” area of the Website. Briefly, when considering a properly carbonated kegged beer, the length and kind of tubing between tap and keg is crucial to achieving a proper amount of foam. The chart on page 65, reprinted from www.kegman.net, explains that the total resistance should equal the desired level of carbonation. If your kegged beer is carbonated to 10 to 14 psi (pounds per square inch), the total resistance of all the tubing between the keg and the tap should equal 10 to 14 pounds.
   
In dispensing beer at home, 5 feet of 3/16-inch plastic beer line will give us the required resistance (5 feet x 2.7 = 13.7 pounds), but what happens when we need five feet of beer line plus  50 feet of metal tube? Fifty feet of 1/4-inch metal tube, for example, would create a resistance of 100 pounds. The answer is larger tubing or more pressure. More pressure will push the beer through, but applying 30 or 40 psi of pressure will over-carbonate the beer.
   
For our project, we calculated that 25 feet of 3/8-inch (outer diameter) stainless-steel tubing — we’re assuming copper has a similar 0.20 pounds of resistance per foot — would offer 5 pounds of resistance, and 6 feet of 1/4-inch (inner diameter) vinyl tubing would add another 4.2 pounds of resistance. Connecting our coil to the tap with one foot of 3/16-inch beer line (another 2.7 pounds of resistance) could give us the right resistance for our carbonation —  9 to 12 psi (5 + 4.2 + 2.7 = 11.9 pounds of resistance.)
   
That’s a great calculation. But it is impossible to get 3/16-inch beer line over a 3/8-inch barb fitting. So our project uses 10 feet of 5/16-inch inner-diameter beer line (8-1/2 feet from keg to coil and 1-1/2 feet from coil to spigot). Unfortunately, that gives only 5.7 pounds (1.7 + 4) of resistance.
   
One answer is to substitute “X” feet of 1/4-inch tube — however much you need  — between coil and tap. Also, 1/4-inch x 3/8-inch double-barb adaptors or “splicers” are available for about a dollar apiece. Stepping down in tube size between coil and tap helps prevent foam. The connection from coil to short hose should be done with a splice.

Making your coil
For my two copper cooling coils, I used 3/8-inch outer-diameter tube. This choice was based on calculations, and because I couldn’t find 5/16-inch tube. I made two coils because I wanted to build a two-tap jockey box.
   
Forming a coil is easy. To avoid flattening the tube, simply take care not to pull too hard when wrapping your tube around a cylinder. The other approach is using a commercial tubing bender, which will cost under $20. I chose to wrap tubing around a form chosen to fit easily inside the cooler. I used a C02 tank as my form. I simply looped the big coil around the cylinder and started wrapping.
   
To secure the completed coils I hammered a bit of scrap tube flat, then formed a bend with the correct radius and slipped it over the coil stack. Then I bent the other end up to fit tightly, making the coil mechanically stable.
   
Commercial coils may have the inlet and outlet ends raised to similar levels. We could have just hacked our copper coil apart like a big Slinky or spring, leaving the inlet pointed one direction at the top and the outlet another at the bottom. Since we will be connecting the outlet (beer out to the glass) to the barbed fitting of the tap with flexible tubing, there is no need for an exact positional match. If you wanted to use flare or compression fittings and mate coil to spigot, you would have to accurately place the outlet side of your coil at the correct height and position to mate with the tap inlet.
   
For our inlet (beer in from the keg) that passes through the cooler wall, again we can rely on flexible tubing. I bent the bottom coil up to the top of the coil to insure that the coil couldn’t sit on the soft plastic tubing and pinch it off. Use a tubing bender — spring-type or other — or you’ll kink the tube.
   
Another concern is “right or left twist,” a feature of commercial coils. This is important when using longer coils or coils that are mechanically connected to the tap. If you’re using these coils, be careful to measure their position, both beer in and beer out, before drilling your tap holes. You want the coil outlets to line up with the spigot. With the coils complete, all that remains is to assemble the taps, screw on our handle, and put it together.

Step-by-step construction
First assemble the materials: cooler, tubing, tap, shank, fittings and tools (you’ll need a faucet wrench). A 50-quart cooler at the local warehouse club cost $20 and provides the potential to move up to three taps or more!
   
To install the spigots, measure height above the cooler floor and left-right distance. Our cooler was 21 inches wide, so I divided in thirds to leave room for a third tap. I measured down 1-1/2 inches below where the cooler begins to thicken and drilled 1/8-inch pilot holes to allow plenty of room for large homemade backing plates.
   
Shanks, big shiny pipes that go through the cooler wall, are available in many lengths and two styles. One style requires you to purchase the correct tail piece and connector fitting. The other, which we used, comes with a barb fitting already attached.
   
The shanks come with big escutcheon plates in front and large nuts behind. I think that lots of use would soon crack the thin inner plastic wall of the cooler, so I backed each shank up with a large, 2-inch by 3-inch piece of 1/4-inch plexiglass scrap. Any rust-free material would do.
   
Once the shank is pushed into the cooler and tightened up, you’ll need to assemble the spigot or tap. The tap male end is splined (it has one ridge) and can be inserted into the shank at any angle. To fasten the collar of the shank to the tap, you need a special faucet wrench. Or wrap a thick rubber band around the shiny chrome and use an adjustable plier.
   
To drill the holes for tap and beer line I used common spade bits, 1/2-inch for the beer line and 7/8-inch for the spigot. If you have a correct size hole saw, even better.
   
OK: The coils are done, the holes are drilled, and I’ve put the spigot and beer line through the holes. Now I’ll join the cooling coil to the spigot and the beer line to the cooling-coil inlet (heat rises, so bring in beer from the top) and clamp all the lines. Why clamp? Such low pressures shouldn’t really need them. But I learn from experience: Our club’s best brewer brought an Oktoberfest to a competition pressurized at 30 psi. No one knew and the inlet line blew off, filling the cooler with beer. So clamp the hoses.
   
All that remains is to clean the copper coil. I’d suggest precleaning the coil with PBW (Powder Brewery Wash) just before clamping the tubing and sanitizing it after that. Do not leave sanitizing solution in the coil between uses. Clean, sanitize and use carbon-dioxide to expel the sanitizing solution.
   
We asked Charlie Talley, of Five Star Chemicals, for the correct method of cleaning a copper coil and preventing metallic off-flavors from developing. Here are his thoughts: “The best way to clean new or used copper brewing materials is with PBW at a dilution of 2 ounces per 2 to 3 gallons of water (stronger for dark, dirty or old copper). Our measurement of free copper in the discharge water after caustic cleaning dropped from 1,700 parts per million (ppm) to just 1 ppm after three uses of PBW. After cleaning and rinsing, sanitize copper coils with Star San. I recommend 2 ounces per 5 gallons.” Stainless-steel coils can be cleaned and sanitized the same way.
   
Copper has been used in brewhouses for centuries, adds Talley. He does warn that prolonged contact between copper and beer will lead to metallic off-flavors. But if you’re simply running your beer through the clean copper coils in our brand-new jockey box, it should be fine.