Headspace For Kegging

[stylus1274]

I'm sure this is somewhere in the forum but I am unable to find it.

I just kegged up a batch and my keg was pretty darn full. I'm wondering what the general rule of thumb is for headspace?

Right now I have about 3 fingers of space before I hit my lid. I'm guessing I have way too much beer in there.

 

[j1laskey]

I leave about an inch of head room from the bottom of the gas in post.

 

[eric19312]

I've overfilled without bad experience. Overfilled to the point the gas post was dipping into the beer.

 

[stylus1274]

OK good to hear guys. I got a bit more liquid out of my fermenter than expected so I was wondering. Could have sworn I read before not to overfill.

 

[doug293cz]

Might take longer than usual to carbonate. The rate of CO2 absorption is proportional to the area of the beer exposed to the headspace. If you fill above the straight sides of the keg, the surface area decreases rapidly as you fill into the curved portion at the top of the keg.

The other thing to watch out for is beer backflow into the CO2 line. This can happen if you reduce the regulator pressure without venting the pressure in the keg. Want to make sure you have a check valve to protect your regulator from beer.

Other than the above, there shouldn't be any issues with "overfilling."

Brew on

 

[Ashevillain]

I remember when u overfill and gas too close when u disconect gas it makes a mess

 

[stylus1274]

Might take longer than usual to carbonate. The rate of CO2 absorption is proportional to the area of the beer exposed to the headspace. If you fill above the straight sides of the keg, the surface area decreases rapidly as you fill into the curved portion at the top of the keg.

The other thing to watch out for is beer backflow into the CO2 line. This can happen if you reduce the regulator pressure without venting the pressure in the keg. Want to make sure you have a check valve to protect your regulator from beer.

Other than the above, there shouldn't be any issues with "overfilling."

Brew on

I guess I can vent some pressure then turn the regulator down then?

 

[doug293cz]

I guess I can vent some pressure then turn the regulator down then?

Yes. Safest is to vent all the pressure, since if you do a short, partial vent, you have no idea what the pressure in the keg is. If you don't have a shutoff valve between the regulator and the keg, then remove the gas QD prior to venting. Then turn the regulator way down, reconnect the QD, and finally raise the regulator pressure to the new setting.

With a shutoff valve, close the valve, turn the regulator way down, vent the keg, open the shutoff valve, and finally raise the regulator pressure to the new setting.

Brew on

 

[stylus1274]

Yes. Safest is to vent all the pressure, since if you do a short, partial vent, you have no idea what the pressure in the keg is. If you don't have a shutoff valve between the regulator and the keg, then remove the gas QD prior to venting. Then turn the regulator way down, reconnect the QD, and finally raise the regulator pressure to the new setting.

With a shutoff valve, close the valve, turn the regulator way down, vent the keg, open the shutoff valve, and finally raise the regulator pressure to the new setting.

Brew on

Yeah I have a shut off valve. Good info. Thanks Doug

 

[Yooper]

I have some really short gas "in" diptubes. As long as your beer is below the "IN" diptube, you won't have any issues. I sometimes check with a flashlight when I get super close, because all of my fermenters tend to end with over 5.25 gallons of beer, and it almost always fits. But I still check, because once or twice I have filled over the diptube.

 

[stylus1274]

I have some really short gas "in" diptubes. As long as your beer is below the "IN" diptube, you won't have any issues. I sometimes check with a flashlight when I get super close, because all of my fermenters tend to end with over 5.25 gallons of beer, and it almost always fits. But I still check, because once or twice I have filled over the diptube.

Screw it, I'll just polish off a couple of glasses to be safe

 

[Ashevillain]

Thats the spirit!

 

[jojacques]

I always fill my kegs to the neck........ any specific reason why I should keep the beer level below the gas tube?

 

[j1laskey]

I always fill my kegs to the neck........ any specific reason why I should keep the beer level below the gas tube?

see post 5

 

[jojacques]

Not sure how I missed that, apologies!
I got a built-in check valve on my regulator + check valves in the co2 manifold...
Guess im safe Thanks!