Keg seal leaking

[pryornfld]

Hey All
I completed a brew and kegged month back. Put keg in fridge 2 weeks ago and today went to check and discovered seal leaked. Can this beer be saved or is it now gone flat and should be thrown out? Been sitting in keg for about a month, put the CO2 onto it today, thus how I found leak. Can't say how long it's been leaking

 

[lumpher]

It should still be fine. There will still be a CO2 blanket covering it. I think we've all had the same thing happen. I just did a keg to keg transfer yesterday for the exact same reason so I could fix the bad keg.

 

[pryornfld]

It should still be fine. There will still be a CO2 blanket covering it. I think we've all had the same thing happen. I just did a keg to keg transfer yesterday for the exact same reason so I could fix the bad

Now I didn't force carbonate the keg, I used priming sugar. It's been sitting in keg for a month before I found leak. So still good you think? I reseated lid and seems fine now.

 

[Dovage]

Even naturally carbing you’ll have a nice blanket of C02 protecting the beer. Should be all good. Get a new seal. Throw it on gas and serve.

 

[Dovage]

Forgot to add. C02 is heavier than air so even without pressure it will stay in your vessel. At least enough to keep out oxygen.

 

[sibelman]

It's common for folks to add some pressure when closing a keg, to seat the seal.

Please note that the imagined CO2 "blanket" is just that: imagined. Gasses mix rapidly. However, the small area of leakage would limit the speed of gas mixing.

Your beer will probably be just fine.

 

[Dovage]

It's common for folks to add some pressure when closing a keg, to seat the seal.

Please note that the imagined CO2 "blanket" is just that: imagined. Gasses mix rapidly. However, the small area of leakage would limit the speed of gas mixing.

Your beer will probably be just fine.

Not sure I agree with you on this. If it mixes that easy how does beer not oxidise if left in a fermenter for 5,6 weeks or longer. After primary fermentation yeast aren’t producing much C02 any longer. Not saying your wrong, just curious.

 

[sibelman]

@Dovage , this has been kicked around a lot. Common sense observations are sometimes at odds with reality. For example, if the CO2 in the earth's atmosphere responded to the heaviness/blanket thing, the surface of the earth would be coated in CO2, with less dense gases above; and we would never have evolved. Instead, we observe that at ordinary earthly conditions, gases mix it up, and the mixture is fairly constant everywhere.

I'm told that, when I uncork a fermenter, this mixing takes place quickly, so that the previously almost pure CO2 inside the fermenter soon becomes ordinary air with plenty of oxygen. This is why oxygen-conscious brewers have become obsessed with "closed transfer", moving beer from fermenter to (purged!) keg with almost no exposure to air.

Re your curiosity: The 5-6 weeks of fermentation take place protected from air by the airlock on the fermenter. During the early, most active phase, the major outflow of CO2 through the headspace steadily dilutes the other gases there -- mostly nitrogen and oxygen -- which are carried out through the airlock along with most of the generated CO2, leaving almost pure CO2 inside the fermenter. This is more a bubble than a blanket. The airlock isn't a perfect seal, but it's apparently damn good at preventing other gases from re-entering the fermenter.

 

[mac_1103]

If it mixes that easy how does beer not oxidise if left in a fermenter for 5,6 weeks or longer.

An air lock will more or less maintain the CO2 atmosphere above the beer. But oxygen will still diffuse in (and CO2 out), albeit slowly. Without an airlock the mixing of ambient air with the CO2 will be much faster. There's no airlock in the case of a leaking keg.

 

[odie]

I'm gonna guess that when the priming sugar was done it was partially carbed. then the pressure dropped when you put it in the fridge, enough to let the lid seal un-seat.

It's also possible that when you added priming sugar that you did not seat the lid with a CO2 blast or skipped keg lube and the carbonation just leaked out as it was "priming".

keg lube is your friend.

 

[Clint Yeastwood]

I like to keep extra O-rings so I don't take an O-ring that has been under pressure for weeks or months and put it in a new keg. My understanding is that it may take a while for an O-ring to rebound from being flattened, so they may not seal as well if they haven't been given some time off. Perhaps others will have input.

You should have some extras anyway, because they do get damaged.

Regarding heavy gases settling, it must be true, because radon. Also, boats have blowers to pump explosive gas (gasoline vapor) out of their hulls in order to prevent the obvious from happening when a spark or a fool with a cigarette enters the picture. Also, if you pump an engine room full of CO2 to stop a fire, you should run the blower before going in so there will be oxygen for you to breathe.

How effective a gas layer is is another question.

 

[ClaudiusB]

I like to keep extra O-rings so I don't take an O-ring that has been under pressure for weeks or months and put it in a new keg. My understanding is that it may take a while for an O-ring to rebound from being flattened, so they may not seal as well if they haven't been given some time off. Perhaps others will have input.

You should have some extras anyway, because they do get damaged.

Regarding heavy gases settling, it must be true, because radon. Also, boats have blowers to pump explosive gas (gasoline vapor) out of their hulls in order to prevent the obvious from happening when a spark or a fool with a cigarette enters the picture. Also, if you pump an engine room full of CO2 to stop a fire, you should run the blower before going in so there will be oxygen for you to breathe.

How effective a gas layer is is another question.

"Regarding heavy gases settling, it must be true"
Havy Gas diffusion with air.

 

[mac_1103]

Density of radon - 9.73 kg/m³
Density of carbon dioxide - 1.977 kg/m³
Density of air - 1.204 kg/m³

 

[VikeMan]

Not sure I agree with you on this. If it mixes that easy how does beer not oxidise if left in a fermenter for 5,6 weeks or longer.

A beer left in a fermenter for 5-6 weeks (presumably with all or some of this time being after active fermentation is finished) and not sealed will pick up more oxygen than one that didn't sit for that long. And that O2 will oxidize some compounds in the beer. Every beer is oxidized. It's a matter of how much.

 

[VikeMan]

The airlock isn't a perfect seal, but it's apparently damn good at preventing other gases from re-entering the fermenter.

I don't know if I would say "damn good" here. But much better than nothing, for sure. Spunding valve even better.

 

[Clint Yeastwood]

Every beer is oxidized. It's a matter of how much.

This should be obvious, but I don't recall seeing anyone say it here before.

If you have a leaky O-ring, the leak should work in both directions, even if the keg is pressurized. Gas molecules are really small, and they move all the time. While CO2 is trying to get out, the 20% or so of the outside air that is O2 is trying to get in, and some of it must succeed. An O2 molecule going through a tiny gap in a seal must be sort of like a gnat flying through a chain link fence.

As for heavy gases settling, here is an interesting video:



If you don't feel like clicking, it shows a guy taking a beaker, scooping a heavy gas up, and pouring it into another container, where it runs downhill and puts a candle out. Even if the gas eventually mixes with the surrounding air, it stays together really well for quite a while.