Priming A Keg With Sugar

[Nick JD]

I just kegged the batch with 80g - I was going for 75 but poured too much in the container on the scales - so 80g it is! It's a hoppy lager.

When I shook the keg up to dissolve the sugar it produced a bit of pressure and I did a leak test on the IN and OUT and the lid and gave it a fart and it's all good so far.

I'd also like to know the physics behind volumes of CO2 being the same, but different in kegs vs bottles.

 

[loikar]

"I'd also like to know the physics behind volumes of CO2 being the same, but different in kegs vs bottles."

BIG! bump

Anyone?

 

[Ross]

That seems to be for bottles that calculator. I've read in a few places that kegs only need half the sugar for priming. Do you use that for keg priming?

I'm not concerned about oxygen in the keg (it'll be taken up by the yeast), but do I need a little bit of pressure to ensure the yeast-made CO2 doesn't leak out the lid before any pressure is built up?

you should be purging the keg of air - The priming sugar wont come close to consuming it.

If you shook up your beer to dissolve the sugar, then you'll have oxidised your beer. Hopefully not to an extent that ruins the final beer.

Cheers Ross

 

[barls]

im thinking it has something to do with me purging the headspace after i fill it. this leaves me part way there to the final pressure required

 

[Nick JD]

you should be purging the keg of air - The priming sugar wont come close to consuming it.

If you shook up your beer to dissolve the sugar, then you'll have oxidised your beer. Hopefully not to an extent that ruins the final beer.

Cheers Ross

Well, that keg was gone five months ago, but thanks for the advice! The keg was so full it was up to the gas post - so no worries there - less headspace than a bottle by far.

Since then, I've given up on natural carbing kegs. Not worth the savings in CO2 - I get 2.3 kg for $16.50.

 

[Dickster86]

I use carbonation drops and find that about 15 drops in a 9.5L keg and that seems to work great. Shake the hell out of it (just like you would a bottle) and no need to add any extra gas. Works a charm. The carbonation drops recommend 1 per 330ml stubbie, so its about half of the recommendation (9.5L / .33L = 28.78). Keen to try priming with dme or just pure dextrose in the future though

 

[Lyrebird_Cycles]

Since this has been resurrected:

Head space in percentage. I bet if you are a math whiz and calculate out the headspace, O2 consumed and replaced, and other factors you would find that bottles require more CO2.

This is NOT the answer. Headspace correction is included in the calculator I wrote and it works the opposite way: the more headspace you have the more priming (per litre beer) is required. This is logically the case, the beer volume needs to generate enough CO2 to bring the headspace into equilibrium in addition to the amount required to achieve carbonation.

I do not know what the answer is.

I suspect it is something as simple as a combination of desired CO2 level being lower in cask conditioned beers and needing to undercarbonate to account for the CO2 absorbed when it is pressurised for serving. Since I don't drink enough to bother with kegs, I can't answer from experience.

 

[RelaxedBrewer]

I use carbonation drops and find that about 15 drops in a 9.5L keg and that seems to work great. Shake the hell out of it (just like you would a bottle) and no need to add any extra gas. Works a charm. The carbonation drops recommend 1 per 330ml stubbie, so its about half of the recommendation (9.5L / .33L = 28.78). Keen to try priming with dme or just pure dextrose in the future though

Just weigh out 15 carb drops and that is how much sugar you need to add.

Are carb drops dextrose or sucrose?

 

[Lyrebird_Cycles]

The Coopers ones are apparently a mixture of about 3/4 sucrose and 1/4 glucose (=dextrose). I'm assuming this is because it's much harder to get a pale hard candy from glucose (tends to make soft candy).

 

[Rocker1986]

I use carbonation drops and find that about 15 drops in a 9.5L keg and that seems to work great. Shake the hell out of it (just like you would a bottle) and no need to add any extra gas. Works a charm. The carbonation drops recommend 1 per 330ml stubbie, so its about half of the recommendation (9.5L / .33L = 28.78). Keen to try priming with dme or just pure dextrose in the future though

Are you trying to oxidise it? There is no need to shake either bottles or kegs; it does nothing to dissolve the drops and the yeast will find and ferment the priming sugar regardless.

 

[Aus_Rider_22]

Sorry to rebump this thread.

I have come to a dilemma. I keg most of my beers and was planning to keg my BIPA this afternoon. But last night my co2 blew and I won't be able to refill until next weekend (co2 refill is available 1hr away but due to weekend opening times I can't make it this weekend.)

I have 18L of this brew and was going to add dextrose and leave it be. I have only ever naturally carbonated a keg once before and I had my co2 to displace the headspace after filling.

After reading through this thread, I am worried that 18L of beer will leave too much headspace and oxidise my beer even after secondary fermentation. Thanks for any help.

 

[mofox1]

Sorry to rebump this thread.

I have come to a dilemma. I keg most of my beers and was planning to keg my BIPA this afternoon. But last night my co2 blew and I won't be able to refill until next weekend (co2 refill is available 1hr away but due to weekend opening times I can't make it this weekend.)

I have 18L of this brew and was going to add dextrose and leave it be. I have only ever naturally carbonated a keg once before and I had my co2 to displace the headspace after filling.
After reading through this thread, I am worried that 18L of beer will leave too much headspace and oxidise my beer even after secondary fermentation. Thanks for any help.

Have you got any other pressurised kegs? If so you can rig up a gas to gas line and purge your newly kegged beer using the pressurised kegs.

Then again, this would leave you with no kegged beer to drink, which IMO is bad. I'd leave it in the fridge and delay the kegging until I have CO2 to spare... an extended cold crash won't hurt.

 

[Aus_Rider_22]

Have you got any other pressurised kegs? If so you can rig up a gas to gas line and purge your newly kegged beer using the pressurised kegs.

Then again, this would leave you with no kegged beer to drink, which IMO is bad. I'd leave it in the fridge and delay the kegging until I have CO2 to spare... an extended cold crash won't hurt.

I have 2 kegs of lager in my kegerator at the moment. They have been lagering for 3 weeks now and are bright as ever, so I don't want to move/disturb them.

The more I think about, I will just keep it simple and bottle this batch. I have plenty of clean bottles and carb drops so I will do that and bring bottle stocks up. No point risking oxidisation on this batch which is tasting suburb just from the gravity taste!

Thanks for your help mofox1, I appreciate it.