[Allen Brown]

On my next batch, I plan on bottling some portion of it and kegging the rest.  Since I am not sure how much I want to bottle, what would happen if I added priming sugar to the whole batch, and then kegged half of it later?  Of course I can split the portions up and scale down my sugar, but I was just curious.

Thanks,

Allen

[mainebrewer]

It'll be fine.
You will likely have a little more sediment in the bottom of the keg that you would if you just force carbed the beer.

[morticaixavier]

Yup, this is the way to bottle if you have the keg available. You can push it into bottles with a little co2. bottle as many or as few as you want and let the rest carb up in the keg. The keg portion might get a bit over carbed but that is easily handled by bleeding off excess pressure and letting the beer come to equilibrium.

[Allen Brown]

Yup, this is the way to bottle if you have the keg available. You can push it into bottles with a little co2. bottle as many or as few as you want and let the rest carb up in the keg. The keg portion might get a bit over carbed but that is easily handled by bleeding off excess pressure and letting the beer come to equilibrium.

Interesting.  So by "come to equilibrium", do you mean that after I bottle whatever amount, I take pressure off the keg, and in essence, let it go flat, before force carbonating?

[morticaixavier]

Yup, this is the way to bottle if you have the keg available. You can push it into bottles with a little co2. bottle as many or as few as you want and let the rest carb up in the keg. The keg portion might get a bit over carbed but that is easily handled by bleeding off excess pressure and letting the beer come to equilibrium.

Interesting.  So by "come to equilibrium", do you mean that after I bottle whatever amount, I take pressure off the keg, and in essence, let it go flat, before force carbonating?

you won't need to force carb the keg. you will need to let the remaining priming sugar ferment out though. once that happens the keg will be carbonated. However, for some reason that is not readily explainable, a large volume of beer requires less sugar per floz to achieve a given carbonation level than a small volume of beer. So for 5 gallons of beer to be bottled in 12 or 22 floz bottles you generally use ~4 oz of sugar. but for the same volume of beer in a keg, to naturally carbonate requires more like 3 oz.

so in you plan you will be adding enough sugar to carbonate the full volume in 12 or 22 floz bottles but only packaging about half of it that way. The half that remains in the keg will carbonate naturally as well. But because of this quirk with natural carbonation the half in the keg will likely end up slightly over carbed. So you bleed off co2 after it is done carbonating and let it come to equilibrium with whatever PSI you WOULD have used to force carb.

[slarkin712]

you won't need to force carb the keg. you will need to let the remaining priming sugar ferment out though. once that happens the keg will be carbonated. However, for some reason that is not readily explainable, a large volume of beer requires less sugar per floz to achieve a given carbonation level than a small volume of beer. So for 5 gallons of beer to be bottled in 12 or 22 floz bottles you generally use ~4 oz of sugar. but for the same volume of beer in a keg, to naturally carbonate requires more like 3 oz.

I believe the difference in priming sugar amounts between kegging and bottling is due to head space.  In bottles, a larger percentage of the container is head space compared to beer volume.  In a keg this percentage of head space is lower.  Thus less CO2 is needed to fill that head space in a keg.  And less CO2 means less priming sugar.

[morticaixavier]

you won't need to force carb the keg. you will need to let the remaining priming sugar ferment out though. once that happens the keg will be carbonated. However, for some reason that is not readily explainable, a large volume of beer requires less sugar per floz to achieve a given carbonation level than a small volume of beer. So for 5 gallons of beer to be bottled in 12 or 22 floz bottles you generally use ~4 oz of sugar. but for the same volume of beer in a keg, to naturally carbonate requires more like 3 oz.

I believe the difference in priming sugar amounts between kegging and bottling is due to head space.  In bottles, a larger percentage of the container is head space compared to beer volume.  In a keg this percentage of head space is lower.  Thus less CO2 is needed to fill that head space in a keg.  And less CO2 means less priming sugar.

that's probably it.

[Allen Brown]

Great, thanks for the info.

However, in my scenario, I would end up with somewhere near 50% head space in the keg, so my typical 3/4 to 7/8 cup of priming sugar should be fine for what's left in the keg.

[euge]

Yup, this is the way to bottle if you have the keg available. You can push it into bottles with a little co2. bottle as many or as few as you want and let the rest carb up in the keg. The keg portion might get a bit over carbed but that is easily handled by bleeding off excess pressure and letting the beer come to equilibrium.

Interesting.  So by "come to equilibrium", do you mean that after I bottle whatever amount, I take pressure off the keg, and in essence, let it go flat, before force carbonating?

It would be better if you primed the entire batch in the keg and then bottle out of the tap once it's carbonated. You bleed off the keg's headspace pressure until the beer flows slowly from the tap. Usually 1-3 psi in the keg is enough to move the beer without agitating it too much. Chill your bottles first- cap on foam.

Pretty much the preferred practice.

[bbogenrief]

I’ve been transferring to bottles from a keg for a couple years. I determine the exact amount of priming sugar based on desired volumes of co2, actual batch size and residual co2 in wort. Boil the priming sugar in 2 or 3 cups water and place in sanitized corny keg. Purge keg with co2. Use co2 to slowly push fermented wort from bottom of carboy into keg through the beer side of the keg. Then you can connect the keg to your co2/tap as you normally would and fill the bottles straight from the tap. I use a bottle filler tube that screws directly to one tap and a second tap connected straight to the co2 to purge bottles with gas. This nearly eliminates exposure to oxygen/air when bottling and is actually easier than dealing with bottle bucket. You bottle as much as you want to bottle, then disconnect the keg and let it condition as if it were just another large bottle. The keg will be under carbonated, but you can still adjust the carbonation of the keg afterwards just as you would with force carbonating. Note: if you leave the keg in the fridge it will not condition naturally.