Carbonating Corny kegs

[johnturn]

Hi, just gassed up my first corny keg with my new favourite home brew in it, just the one one question. If I gass up to say 15psi in the next 24 hours should the pressure still be 15psi or should it be lower because the gas is being absored into the beer. Dont have a regulator at the moment so just want to make sure I dont have a leak or anything.

Thanks John

 

[Wez]

Hi John & Welcome :thumb:

I'd expect it to drop a bit due to absorbtion, and the colder you store the corny is the more the beer will absorb.

I'm not a corny expert so hopefully someone will be along shortly to put you (us) straight but...

If it hits zero PSI tomorrow you have a leak if it's down to say 10 PSI it's absorbed 5psi :thumb:

Cheers, Wez

 

[BrewStew]

the beer will absorb some gas, so it's likely it'll lose pressure even without leaks.

it's a bit late now, but it's worth checking for leaks when empty...you can check now but there's probably not alot you can do about it... so just mix up a soapy solution of water and brush it around the seals, poppets and PRV, and look for bubbles. if there are none then you're sorted ... just keep it topped up as it absorbs the gas :thumb:

i keep my kegs at 1PSI per degree C that they're stored in.. so if my room temp is 18'c, then i set it at 18PSI and leave it that way for a bit longer than a week, then drop down to serving pressure (about 10psi)

hope this helps :thumb:

 

[johnturn]

Superb, thanks for the welcome and fast replies. I did do the pressure test with the soapy water before hand which did seem fine. Took the time to clean the keg, replace all the seals and steralize everything porperly. Just thought I would check but I think its ok. Put 15psi in the keg and six hours later its dropped about 0.5psi. As for 1 psi per degree, how would you describe the carbonation level.

Best regards,

John

 

[BrewStew]

i would describe the carbonation as about 2 volumes :geek:

in english that means about down the middle for most beers. depending on style they range from 1.6 to 2.4 IIRC. 3 is like fizzy pop... 1 is flat as a witches proverbials

nice one on the seals. although i'm surprised the pressure dropped that quickly... 6 hours your say? :hmm: give it another top up and see if the pressure drops that much over the next six hours.

co2 absorption seems to slow exponentially lots to start with and slows down as it absorbs more.

 

[johnturn]

Will do, actually its more like 8 hours now, I haven't got a clue how much it should drop but I didn't think half a pound sounded that much. What would you think the loss would be for the first 24 hours then.

 

[BrewStew]

i honestly cant answer that. all my kegs are hooked up to a regulator board so they get topped up as and when they need it.

i can say however that i leave my regs and gas turned off when i'm not using it, and just top the kegs up every day (incase i get a leak i wont lose a whole bottle of gas overnight.... again!) and for the first two or three days, the regs literally squeel cos of the amount of gas they're shoving back in. they settle down after 3 or 4 days though. after a week they barely let in any gas at all.

 

[johnturn]

Ok got you. So over the next 24 hours I should be expecting a big drop in pressure, after a week or so the pressure drop slows down and a few days later I should have beer. Thanks for the info. Have just gassed up again and I'll check again in the morning. Maybe its because the beer is at room temp about 22C, think the pressures is only at 15 so that may be why. will put it in the fridge overnight and check it in the morning. I think the fridge runs at about 5C so does your logic for the pressure apply to fridge temps as well.

All the best John

 

[BrewStew]

the physics apply, but unfortunately your cornie lid seals wont. if you want to run a pressure lower than 10psi, you may need to look into a softer compound of rubber o-rings for the lid. these o-rings depend on internal pressure to keep them pressed shut and a good seal to be made, so the standard harder compound may not be up to the job.

you can by all means have a higher psi than ambient temp for short periods of time, say overnight... but i wouldn't go any longer or you'll force too much gas into the beer and end up pouring foam.

as an example, on new years eve i'd just racked some turbo cider. it was flat a witches tit with only 6 hours to go till the party. so i filled the kegs to 30psi, and left them outside in -2'c weather. when the party kicked off i let the gas down to the ambient temp under my bar and they were just starting to show enough sparkle to give the cider some lift.. was still flat, but better than totally flat. if i'd left it like that overnight it'd have been foam to the last glass :lol:

 

[johnturn]

I can set the fridge to 13C gas the keg to say 15 for week. Does that sound better.

 

[BrewStew]

depends on how much of a rush you are to drink it mate

if you want to get started on it in a couple of days and dont mind drinking it slightly "green", putting it in the fridge overnight at 15psi at 5'c then raising the temp to 13 in the morning should give it a good kick start in the right direction, provided you can keep topping it up regularly cos it'll absorb more when colder and under that pressure.

or for simplicity and to be sure there's enough gas left in the keg to keep it under pressure until you top it up again... going 1 for 1 at room temp is a decent bet too if you dont think you'll be around enough to keep topping it up :thumb:

 

[johnturn]

Yup, 1-1 sounds best. The bedroom is quite cold usually around the 16c so will go with the 1-1. Dont want to put it in the fridge and find the pressures not been enough to keep the seals tight and spoiling the beer.

Thanks for taking the time to answer a fair amount of newbie question, I'll leave you to enjoy the rest of your evening.

Regards,
John

 

[BrewStew]

glad to have helped... i'm off to bed :thumb:

 

[johnturn]

Same here.

Thanks again.