Keg Priming

[RustyHorn]

Can someone explain to me why I need less sugar to prime a keg compared to priming bottles?

 

[kh54s10]

The only thing I can think of is that when you pressurize for dispensing you are adding co2. I would not think that at serving pressure you would get much more carbonation so I would think the amount of sugar would be the same. I have never prime carbonated a keg though.

 

[Jag75]

I'm not sure . It should be the same if the amount and temp are the same .

 

[RPh_Guy]

Can someone explain to me why I need less sugar to prime a keg compared to priming bottles?

You don't.

 

[RustyHorn]

You don't.

Hmm... Beersmith is telling me different. What am I missing?

 

[kh54s10]

It looks like it is calculating based on bottled co2 pressure AND sugar for the keg carbonation. Doesn't seem right to me.

 

[purplerat]

I believe it has to do with headspace. The combined headspace of all your bottles is significantly greater than the headspace in a single keg assuming the keg is nearly full. As a result less of the CO2 produced goes into the headspace and more goes into the beer thus requiring less overall be produced.

 

[RustyHorn]

I might go with the beersmith prediction (Or just a little over) then if need be, partially force carb. It's Probably better than over carbing!

 

[Jag75]

Just curious but if your kegging why wouldn't you just hook up to co2 and force carb ? Or set it and forget it ?

 

[Sadu]

Yep it's to do with the amount of headspace. With kegs you don't need to get it perfect as you can always force carb if it's a bit low or release pressure if a bit high.
Should take about a week at room temperature to carbonate.

 

[bleme]

Just curious but if your kegging why wouldn't you just hook up to co2 and force carb ? Or set it and forget it ?

1. Keg priming scrubs the oxygen picked up in transfer.
2. You can do it when you don't have room in your kegerator.
3. Sugar costs less that CO2 for many.
4. Many believe you can taste the difference.
5. Reliable results faster.

 

[Jag75]

1. Keg priming scrubs the oxygen picked up in transfer.
2. You can do it when you don't have room in your kegerator.
3. Sugar costs less that CO2 for many.
4. Many believe you can taste the difference.
5. Reliable results faster.

Ahh I didnt even think of that .

 

[Cavpilot2000]

1. Keg priming scrubs the oxygen picked up in transfer.
2. You can do it when you don't have room in your kegerator.
3. Sugar costs less that CO2 for many.
4. Many believe you can taste the difference.
5. Reliable results faster.

Have you tried spunding?
All the benefits with no need to buy sugar, and better at scrubbing oxygen. The only downside is getting the timing right.

 

[Gnomebrewer]

It's not because of the volume (capacity) of headspace. Headspace is similar for a keg as it is for the same volume of beer in bottles. Someone on here years ago did some measurements of each and found that the headspace in a keg is actually slightly higher. I think (just guessing) it's a combination of two things to do with headspace though:
1. Most brewers, after filling the keg, purge then pressurise the headspace in the keg, thus it's already full of pressurised CO2.
2. When you open a bottle, you lose the pressure from the headspace; this equivalent pressure/CO2 is never lost from a keg.
When I keg primed (I mostly spund now), I used about 2/3 of the sugar that was needed for the same volume in bottles.

 

[Bubbles2]

1. Keg priming scrubs the oxygen picked up in transfer.
2. You can do it when you don't have room in your kegerator.
3. Sugar costs less that CO2 for many.
4. Many believe you can taste the difference.
5. Reliable results faster.

N.M