Kegging 101 (2)

Next on the list is your regulator. Since your tank is filled with liquid CO2, the pressure inside the tank at room temperature is about 800 psi. The regulator takes the 800 psi and allows you to dial it down to a more usable pressure of 0 - 50 psi or so. All regulators for CO2 are about the same, your only choice is between one with a single gage, and one with two gages. The single gage type reads the pressure into the keg, which is really the only pressure that you need to know. However, with the dual gage regulator, the second gage tells you the pressure inside the CO2 tank. As long as there is liquid CO2 in the tank, this gage will always read 800 psi at room temperature. However, once the liquid CO2 is gone, the pressure in the tank will begin to fall. With the second gage, you can actually see that the pressure is falling, signaling that it's almost time for a refill. With the single gage, you won't know the tank is empty until the pressure in the tank falls below your serving pressure, and by then, Murphy says you will be in the middle of a big party with no way to refill the tank. The difference in price for the extra gage is less than $10 in most cases, and worth the cost for this reason.

Now comes the issue of dispensing. You will need a faucet of some type to dispense your beer. There are two basic types. The first is the cheapest - the picnic or cobra head tap. The picnic tap is a small plastic valve that fits into the end of a hose that connects to the liquid-out connector. The other type is the metal beer faucet that we see at restaurants and bars. The picnic tap is a convenient and cheap way to dispense your beer and it's the most widely used method by homebrewers. However, it's biggest drawback is that you cannot dispense beer with it at typical carbonation pressures. Let's say that I have a Pale Ale at 45 ° F and 12 psi. If I attach a picnic tap and depress the handle, the beer will come shooting out into my glass and provide me a nice glass of beer foam and probably beer stains on my shirt. To properly use the picnic tap, you need to turn your regulator pressure down to the 1 - 2 psi range and allow the beer to gently exit the tap and provide a nice civilized glass with a good foam head. This is fine, however, you can't store the beer long term at 1 - 2 psi or else you will lose your carbonation. A few hours is probably okay, but longer than that, and the beer will tend to go flat. Therefore, the pressure must be turned back up to 12 psi when the beer is stored. The beer faucet, however, provides enough resistance to the pressure in the keg that 12 psi results in a nice steady flow of beer into the glass with a perfect head. The difference is in the design of the faucet and the resistance it provides to the flow of beer.

Picnic Tap Beer Faucet

The tubing that is used to deliver beer to the faucet also provides resistance to flow. However, no reasonable amount of beer line will allow you to dispense beer at storage pressure through a picnic tap. So, if you are using picnic taps, attach just enough tubing to the picnic tap so that dispensing is convenient. Adding extra tubing won't keep you from having to dial the serving pressure down on the keg, period. Varying the tubing lengths on beer faucets however, greatly affects serving pressure. Depending on your kegging configuration and the beer style you are serving, you want to attach enough tubing so that you can store and serve at the same pressure. This is called "balancing the system". Different sized tubes and the elevation of the faucets relative to the keg offer different resistance and can be adjusted so that a perfect pour can be achieved. To determine the beer line size and length required for a beer faucet system, visit www.kegman.net.

So now you have your keg, your CO2 tank, your regulator, and your faucet, and it's time to put beer in the keg. The beauty of kegging is that you can kiss your priming sugar days goodbye. Using your CO2 tank, you can actually force CO2 into your beer and achieve carbonation very quickly in a matter of a few hours. For the purists out there, yes, you can add priming sugar, seal the keg and wait a couple of weeks, but why? Force carbonating is so much easier, predictable, and accurate, it's a no brainer. To force carbonate, chill the keg first. Cold beer holds more CO2 than warm beer, so the beer needs to be cold before the CO2 can dissolve into solution. Typically, beer carbonation is measured in volumes. A beer carbonated to 2.5 volumes means that there are 2.5 grams of CO2 dissolved in 1 liter of beer. Guidelines for CO2 volumes in beer styles can be found in the BJCP handbook; but this is not really useful when trying to figure out what pressure to set your regulator at to carbonate your beer. The CO2 volumes are a function of the beer pressure and temperature; when the beer warms up, the volumes will decrease unless there is a corresponding increase in pressure. Luckily, someone did the math and came up with a chart for the pressure vs. temperature relationship, which can be seen here. The numbers highlighted in yellow on the chart are the typical values that most beers will fall under. I have found that for nearly all of the beers I make, a pressure of 12 psi at 45 °F works well, which is approximately 2.3 volumes.

The last page of this article describes a procedure for force carbonating your beer and a complete table of CO2 Volumes vs. Temperature and Pressure. Click here to view this page.

So, in conclusion:

1. Choose a keg type: ball lock or pin lock. Pin locks are slightly shorter and larger in diameter, ball locks are more readily available.

2. Buy a keg that has already been reconditioned. It's worth the extra $20.

3. Buy a dedicated refrigerator for your kegs. Used reliable refrigerators can be found in the local classifieds and used appliance stores for $50 - $75.

4. Smaller 5 lb CO2 tanks don't last nearly as long as the 15 - 20 lb tanks. Portability can be achieved by buying the small CO2 injectors and leaving the tank at home.

5. Buy a dual gage regulator so that you can tell if your CO2 tank is almost empty long before you actually run out. The cost is less than $10.

6. Picnic taps are an inexpensive way to dispense beer but the pressure on the kegs must be lowered for serving, than raised for storage. Beer faucets allow serving the beer at storage pressure but are more expensive.

7. No realistic amount of tubing can be added to a picnic tap to allow serving at storage pressures. Attach only enough tubing for convenience, then adjust the pressure accordingly.

8. Force carbonation can be achieved in a few hours by shaking the keg under pressure and adjusting the shaking time to achieve the desired carbonation.

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