how much head space needed for keg?

[mgable]

I am getting ready to keg for the first time and am wondering how full do you fill the kegs? right to the top ar leave some head room?

 

[Aleforge]

If you made a 5 gallon batch, it won't top off the cornie. My last 5 gallon batch left about 6 inches of headspace, but I also leave a few inches in my carboy to avoid extra trub getting sucked in.

In any event you can fill it as high or low as you want, as long as your carb right away and purge out the Oxygen!

 

[mgable]

I brew 5 1/2 gallon batches so I can fill as full as needed and leave the trub.

 

[ShortSnoutBrewing]

I've always been told to leave about an inch between the top of the beer and the bottom of the gas in tube.

 

[Blender]

I brew 5 1/2 gallon batches so I can fill as full as needed and leave the trub.

Me too. I can fill it to about an inch of the gas in tube as Kilted does.

 

[david_42]

Leaving some space between the gas tube and the beer is a very good idea. First, you reduce the chances of back-flow; second, you need surface area between the CO2 and the beer for carbonation.

 

[Special Hops]

^ The level of beer in the keg does not affect surface area. Unless you literally fill up to the head of the keg.

 

[john from dc]

i've heard the surface area argument as well, but assuming you purge all the oxygen out the exposed surface area would be the same whether the gas in tube was submerged or not. the pressure would be the same over the entire surface as well.

the reduced chance of beer flowing into your gas tube and mucking up your regulator is a good enough reason to leave an inch of clearance, imo.

 

[Aleforge]

^ The level of beer in the keg does not affect surface area. Unless you literally fill up to the head of the keg.

I'm not a scientist but I would think the same. As it goes up and down in the keg the surface area is exactly the same. Maybe he meant that as if you topped it off with zero surface area?

 

[littlehop]

What if the keg was layed down on its side.

 

[Arneba28]

i've heard the surface area argument as well, but assuming you purge all the oxygen out the exposed surface area would be the same whether the gas in tube was submerged or not. the pressure would be the same over the entire surface as well.

the reduced chance of beer flowing into your gas tube and mucking up your regulator is a good enough reason to leave an inch of clearance, imo.

No the surface area changes if you do the speed force carbonation with the chill, shake, shake, shake, drink method. With the keg on its side it will change the surface area. However, you still need to leave a little head space so that when you shake this keg you actually get some type of motion out of the beer and not just shaking a solid corny back and forth for ten minutes.:cross:

Beer going into the gas tube is of very limited importance. Almost all regulators that are used now have back flow stoppers on them, or one way valves so that this cant happen and screw up your regulator.

 

[Special Hops]

FWIW I have filled it past the dip tube. I purged the keg with CO2 prior to filling and I had a bit extra - so I just kept filling it. Had no issues.