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by Byron Burch, Robyn Burch and Gabe Jackson
Home brewers sometimes show an aversion to the practice of bottling. Over the years, we’ve been able to codify that into something we like to call Burch’s Third Law: “The tendency of a home brewer to look favorably on the idea of kegging homebrew is directly proportional to the number of bottles washed during the course of one’s home brewing career.”
Logic of the Soda Keg
One of the best draft containers for homebrewers is the five-gallon soda syrup keg (also called cornelius keg, corny, ball lock and pin lock keg). The first reason is the convenience of the five gallon size. Five or ten gallons tends to be the normal batch size for most of us, and that makes it almost too easy to resist, especially for those who really want no more bottle washing whatsoever. That’s not to mention that half or quarter barrel kegs are harder to carry around. There’s also the convenience of needing only a few standard tools, instead of special wrenches, and the speed with which the quick disconnect fittings allow you to make an emergency change when you run out of beer. Most important of all, is the fact that this is an excellent system for draft beer, however you choose to work with it.
Natural Carbonation vs. Force Carbonation
More than one way is available to carbonate your beer. The first is to “bottle” condition your keg. In this case, you prime your beer in the keg after fermentation is finished using half a cup of corn sugar. The keg is then sealed up and set aside for a week or two until your beer has had a chance to fully carbonate. The disadvantage of keg conditioning is that the yeast has to be active in the keg in order to carbonate the beer. Because the yeast is converting the sugar into CO2, a new sediment layer is formed. There are three ways to avoid getting sediment into your glass. You can either cut an inch off of the bottom of your beverage downtube with a pipe cutter so that it rests above the sediment layer, replace the metal downtube with a floating pickup tube, or assume that you will discard the first several pints of cloudy beer.
Eventually, most homebrewers move to force carbonation. There are a number of reasons to force carbonate the keg. First of all, this practice leaves the keg virtually sediment-free, which means you can leave the downtube uncut, and still draw beautifully clear beer right to the bottom. Second, the kegs are fully carbonated in three days time, and around any house, that can be an important consideration.
Bottling some beers may still be important for parties, club meetings, or competitions. If you would like to have some bottled beer on hand, for such events, siphon as much of the beer as you would like to serve on draft into the keg and reserve the rest to bottle. Make sure you are ready to bottle on the same day that you are kegging. We recommend you use 2 1/2 Tablespoons of corn sugar for each gallon you are bottle conditioning. (Bottling instructions can be found here).
Filling the Keg
Rinse out, clean and sanitize your keg before filling it. Use either TDC™, Proxycarb or PBW™ for cleaning. Use BTF™ or Star-San™ for sanitizing. If it is not too troublesome to produce a couple gallons of boiling water, you may partially fill the keg with boiling water before beginning the cleaning process. Allow the boiling water to pasteurize the keg for a while, then top with cold water and add your cleaner. While the sanitation of the kegs is underway, go ahead and take steps to sanitize all of the equipment you will be using for moving the beer including through your beverage lines. At this point, you’re ready to keg!
Elevate your secondary fermentor to siphon your beer into the keg. Before you fill the keg, you should force out any air in the keg with CO2. CO2 is about 50% heavier than air. As you pressurize the empty keg (10-15 PSI is fine), the CO2 will naturally fill the lower part of the keg. Vent the pressure using the lid relief valve. Pressurize the keg again, and vent it again. Do this 6-8 times to force the air up and out of the keg. Now you may transfer the beer by siphon. When you remove the lid of the keg to fill it, you will notice it is filled with a visible cloud of CO2. Go ahead and fill it with beer. After transfer, measure the temperature with a sanitized thermometer or LCD thermometer sticker attached to the keg. Keep the temperature recorded to refer to later. Seal the keg lid so it’s ready for carbonation. Pressurize and vent a few more times to remove air from the headspace that may have entered during transfer.
Setting Up the Draft Hoses & Gas
To attach your beer line and spigot/faucet, begin by heating up some water on your stovetop or in the microwave and put the ends of the tubing in the hot water. The 3/16” tubing we recommend is slightly smaller than the 1/4” hose barbs on the spigot/shank and the black beverage disconnect. Heating it will allow you to easily slip the tubing over the hose barbs. Now attach the gas line to the regulator and secure a tight fit with a stainless steel clamp. Then attach the other end of tubing to the (gray) gas quick disconnect and secure tubing with a stainless steel clamp. Hook up the gas to the IN post of the keg and turn on the gas at low pressure.
When your beer is safely in the keg, and your gas and draft lines are all assembled, you can proceed to force carbonate the beer.
Kegs must be kept cold and under constant pressure for good draft flow. First, turn the screw on your gas regulator clockwise until you reach your desired pressure. Having the beer as cold as 38° F. and setting the gauge at 12 PSI is a great place to start. If your temperature isn’t that cold, adjust your pressure with this carbonation chart, excerpted from Brewing Quality Beers by Byron Burch.
Even with the beer very cold, you need intimate contact between the gas bubbles and the beer to get the gas dissolved. With the gas on, turn the keg upside down and rock it back and forth for 5-10 minutes. This allows the CO2 to bubble out of the gas inlet tube and on up through the beer. Alternatively you can use a keg lid fitted with a diffusion stone to increase the contact. Now you can disconnect the keg and put it back in storage (cold storage is preferable) for three days. The beer can then be hooked back up to the CO2 dispensing system.
Go ahead and assemble your dispensing system once the beer has had a chance to carbonate, usually several days to a week. Vent the keg to release any built up pressure. Attach the beverage quick disconnect to the OUT post on the keg. Attach the gas quick disconnect to the IN post on the keg. Once everything is connected put everything back into the refrigerator.
Set the delivery pressure after you turn on the gas and open the gas valve on the regulator. Adjust the regulator screw to the appropriate PSI. About 12 PSI is usually a good place to start. Dispense and adjust the PSI up or down according to the level of carbonation you desire. Now you can sit back and enjoy your very own draft beer as well as your newly found freedom away from the tiresome task of bottling. On behalf of all of us who have also made the leap we are happy to welcome you to Burch’s Third Law of home brewing.
For a more detailed discussion on carbonating your beer and understanding how to balance your draft system, including keg line balancing, please read this guide by staffer Joe Hanson-Hirt.
A detailed instruction that delves deeper into the factors affecting carbonation and successful draft service.