Gas in keg

[Damfoose]

I have had 4 pints from my keg tonight ! but its out of gas its a cheep keg with out a gas adapter on the top ..... How can I get my keg to build up enough gas so im able to take more beer from it with out running out so soon or is the only real option getting a new top with a gas adaptor so I am able to keep the gas pressure up.

[ADDLED]

Hey Dam, is this the same beer that youve been conditioning for a week?
Maybe it needs longer to build up a bit of gas so maybe leave it a few more weeks. But I also read that 2nd ferment takes only 2-3 days so now im confused....

[Horden Hillbilly]

You will need to change your cap to one which can take gas. I am assuming that it is a 2 inch cap as it is a budget barrel, you will need one of these, along with a Co2 bottle.

Did you give your cap & O ring a smear of vaseline? This helps seal the barrel as well, 4 pints does seem a small amount before you ran out of pressure to me.

[Jim]

The amount of beer you can pull from a keg without a CO2 injector depends partly on how much air space there is above the beer. If there isn't much, you might well only get 4 pints before the pressure runs out.

[Damfoose]

The amount of beer you can pull from a keg without a CO2 injector depends partly on how much air space there is above the beer. If there isn't much, you might well only get 4 pints before the pressure runs out.

Thanks Jim this does seem about right as it was a full keg as I had only filled it last week.

Nothing a quick trip to Leyland wont fix though

need to see if they have This

[ADDLED]

The amount of beer you can pull from a keg without a CO2 injector depends partly on how much air space there is above the beer. If there isn't much, you might well only get 4 pints before the pressure runs out.

Hi Jim, thats interesting - so does that mean that you need a decent headspace above the beer for CO2 to develop enough to give you decent enough pressure for long-term conditioning and dispensing? Ive been trying to bet my head round it (but cant), so whats the science behind that?
Also I know that CO2 is heavier than oxygen so is there any benefit of trying to purge the oxygen that would sit at the top of the barrel to minimise the risk of possible oxidisation spoilage, or doesnt it matter?
Thanks
Obi

[Damfoose]

From what I have managed to work out in regards to beer mechanics ( Hick ) the beer will only create so much pressure in the barrel depending on sugar and yeast and it will only create so much at a given time also the barrel will vent past a certain pressure so it does not pop . So newly barreld lot almost fills the keg leaving not alot of room for the gas. The more beer you drink ( hick ) the more room for the gas so it should have enough to push the beer out for a decent number of pints , personally 5 is enough for me as I will have had enough by then any way

[Jim]

The amount of beer you can pull from a keg without a CO2 injector depends partly on how much air space there is above the beer. If there isn't much, you might well only get 4 pints before the pressure runs out.

Hi Jim, thats interesting - so does that mean that you need a decent headspace above the beer for CO2 to develop enough to give you decent enough pressure for long-term conditioning and dispensing? Ive been trying to bet my head round it (but cant), so whats the science behind that?
Also I know that CO2 is heavier than oxygen so is there any benefit of trying to purge the oxygen that would sit at the top of the barrel to minimise the risk of possible oxidisation spoilage, or doesnt it matter?
Thanks
Obi

If you have the Big Book of Brewing, there's a good explanation of it in there, if not, you'll have to make do with my effort:

Basically, if the volume of the head space is, say 1/2 gall, and you dispence 4 pints (also 1/2 gall of course) then the pressure in the head space will half (obviously, if left for a few days, the pressure will be restored by CO2 coming out of solution in the beer below).

If you have a 1 gall head space, you can dispence 8 pints before the head pressure reduces by half.

Re filling with CO2, yep; many people purge there casks with CO2 before filling for exactly the reason you suggest.

[ADDLED]

Thanks Jim, excellently put.