kegging carbonation

I was wondering how exactly does a keg work? You put your beer in it and hook up the CO2, but when you pull the lever what happens that makes your beer become carbonated? Is it blasted with CO2 when the lever is pulled? Or is there a constant flow into the keg to carbonate it over time? I hope this question isn't too dumb, I've never kegged anything before!

EricR said:

I was wondering how exactly does a keg work? You put your beer in it and hook up the CO2, but when you pull the lever what happens that makes your beer become carbonated? Is it blasted with CO2 when the lever is pulled? Or is there a constant flow into the keg to carbonate it over time? I hope this question isn't too dumb, I've never kegged anything before!

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Co2 is absorbed into the beer with pressure. If you carbonate naturally like in bottles the yeast eats the priming sugar and builds up pressure and the beer absorbs it just like a big bottle. with force carbing Co2 from a tank is applied at a certain PSI, depending on how much carbonation you want, and the temp of the beer. Kegs have a dip tube that goes to the bottom and the pressure in the keg pushes it out.
....scurries to kegorater tops off glass...
When the lever (tap handle) is pulled its basically a valve that allows the already carbonated beer to pour into the glass.

It is connected to CO2 the whole time, providing a constant pressure. Over time CO2 will equalize in the headspace and beer. CO2 dissolves in beer easier at colder temperatures, which is why you need less pressure with colder temperatures, and much higher pressure if you were to carbonate at room temp. When you pull the lever it just draws beer from the bottom of the keg. The pressure in the keg forces the beer out once you open the tap valve by pulling the lever. The constant pressure from the CO2 tank keeps steady carbonation. If you were to carbonate the beer, then remove the CO2 line, over time you will lose carbonation due to increased headspace since pressures will always equalize. You will lose serving pressure as well. This is all why it's important to keep CO2 on it at all times.

If you're wondering about hand pumps. Those bring in outside air to keep enough pressure to dispense the beer. This also oxygenates the beer, making it taste terrible after a few days or so.

Hope that helped.

Wow guys! Thanks for the thorough explanation, now I actually understand what's going on in there!