Air Lock During Keg Dispensing

[ShetlandBrewer]

I kegged a 23 litre batch of bitter adding 6oz o sugare (from memory).
The ionitial pints poursed slowly, but with lovely creamy head, but thereafter there was obviously a pressure differentail of sorts as I could not pour from the keg without letting a little in air in the barrel via the top screw cap.

My physics are probably failing me here but I haven't read of this on the boards and wondered "is it just me?"

[orlando]

My physics are probably failing me here but I haven't read of this on the boards and wondered "is it just me?"

No, usually when drinking cask conditioned beer the beer engine will "pull" (hence the word draught) the beer from the cask through the pipework into your glass, but can only do so if air is allowed into the cask (through the hole left by the removal of the spile). This is fine if the cask is going to be drunk in about 3 days or less. If left any longer the microbes dragged into the cask will eventually turn the beer off, and of course all the time the cask is open it will lose CO2. When we keg beer we usually want it to last awhile and that means excluding air and although the generated CO2 will "push" the beer out once that is exhausted the beer will stop flowing and can actually drag air back in through the tap, potentially stirring up the sediment and clouding the beer. So what to do, well if the cap has a valve then injecting more CO2 will help to continue pushing the beer out, or, as you found you can just crack the lid, at that point you have compromised the beer and now need to get on with emptying, not a problem if a party, bit more if you're on your own. If this is your circumstance that's your answer, if not replace the cap with one with a valve, S30 type preferably, that way you can use a small gas cylinder rather than a disposable sparkler type bulb.

[ShetlandBrewer]

My physics are probably failing me here but I haven't read of this on the boards and wondered "is it just me?"

So what to do, well if the cap has a valve then injecting more CO2 will help to continue pushing the beer out, or, as you found you can just crack the lid, at that point you have compromised the beer and now need to get on with emptying, not a problem if a party, bit more if you're on your own. If this is your circumstance that's your answer, if not replace the cap with one with a valve, S30 type preferably, that way you can use a small gas cylinder rather than a disposable sparkler type bulb.

Great explaination Orlando and satisfies my suspscions.
My issue with the valve and CO2 is that I can't get them delivered here so will need to wait until south and travelling by ferry when I can bring back a stock. You reinforced my commitiment to S30 valves and CO2 injection.
As an aside, by way of experimenting I poured the last of the brew into 2 x 500ml bottles and added a CO2 tablet drop to see what happened. No surprises if you just said to yourself "nothing".

Cheers

[orlando]

As an aside, by way of experimenting I poured the last of the brew into 2 x 500ml bottles and added a CO2 tablet drop to see what happened. No surprises if you just said to yourself "nothing".

I think you're referring to carbonation drops. If so these are just sugar in a handy size for dropping into a bottle after racking off the beer after it has first fermented. They of course need yeast in the beer to effectively ferment and produce the CO2, and a tiny amount of alcohol. Given enough time it might just do it, but, by exposing the beer to air you run the risk of infection and the staling properties of oxygen. If you have any bottles left leave them for a couple of months in the warm and see what happens, you never know.

[ShetlandBrewer]

As an aside, by way of experimenting I poured the last of the brew into 2 x 500ml bottles and added a CO2 tablet drop to see what happened. No surprises if you just said to yourself "nothing".

I think you're referring to carbonation drops. If so these are just sugar in a handy size for dropping into a bottle after racking off the beer after it has first fermented.


If you have any bottles left leave them for a couple of months in the warm and see what happens, you never know.

Now don't I feel like a complete doofus! This makes absolute sense and why others have said not to bother with these and just use sugar
I have one left which had a drop put in. I'll keep it for a while as an experiment.

[orlando]

Now don't I feel like a complete doofus! This makes absolute sense and why others have said not to bother with these and just use sugar
I have one left which had a drop put in. I'll keep it for a while as an experiment.

Don't beat yourself up, you don't know what you don't know, this is what these forums are for.