Does a keg spoil after you have drawn the odd glass?

[HeavensBrew]

I only have small 5L stainless steal kegs (DarkFarm's), but I don't drink a lot. My question is whether the beer spoils once it has increased head space (drawn a pint or 2) and if there is a rule-of-thumb on how quickly an opened keg should be consumed?

PS. Don't have this issue when it's summer BBQ's without Covid. I'm more likely to run ot on those occaissions.

 

[obscure]

The longest I’ve kept an open five litre keg for is about six weeks and it has remained fine, if left for more than a couple of weeks without drawing anything off the tap handle can get a bit stiff but again so long as it’s kept under pressure the beer seems to keep just fine.

 

[terrym]

In my view if you don't allow any air into your kegs as you slowly empty them, and minimise the amount of air in the kegs at the initial fill, it should keep as long the same beer kept in bottles.

 

[HeavensBrew]

Thanks for the feedback. Guess I just need to ensure I add more gas before I put the keg away (after drawing off beer).

As a bonus question.... Should the gas gannister remain connected when you force carbonate (whether over weeks or minutes)? Or do you reach the target PSI and disconnect?

 

[JockyBrewer]

As long as you're pushing the beer out of the keg with CO2 and not letting any air in, the beer will stay fine for a long time.

If you put CO2 into the keg once and disconnect it, you'll find that the pressure drops in the keg as the CO2 is absorbed by the beer, so when force carbonating you generally leave the CO2 connected at the desired pressure.

If you can't leave CO2 connected then you just need to add more pressure and top it up when the pressure drops back. After each top up it'll take longer for the pressure to drop.

When I was unable to leave CO2 connected I'd stick 30psi into the keg and then attach a gauge (a spunding valve with the valve fully closed) so I could see the pressure in the keg. I'd top it back up to 30 psi every few hours for a couple of days, and then I'd leave it to see where the pressure dropped to. If I'd overdone it then I'd use the spunding valve to slowly release pressure. If not then I'd hit it with another 30psi and then see where that dropped to.

 

[Brewnaldo]

I currently have a keg which was filled 46 days ago and the beer is beginning to darken. Not sure how this could be as it has been under CO2 the entire time.