Author Topic: Pressure drop when carbonating my keg  (Read 8541 times)

Offline jcech344

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Pressure drop when carbonating my keg
« on: December 07, 2016, 01:19:53 PM »
I have just packaged off my first batch in a keg.  Everything went well and I set the pressure to 25psi initially (70F temperature, American IPA) looking for 2.5 volumes of CO2.  I am in not hurry to have the beer fully carbonated quickly preferring to take time and get it right.

What I have noticed is that the pressure drops with time.  The co2 cylinder has 600 psi and is unchanged by this drop, but the keg pressure has dropped to <20 psi within an hour.  Is this expected? Do I need to open the value more to move it back up to 25 psi?  Will it stabilize at a pressure and how will I know if it has reached the target co2 uptake?

Thanks
John

Offline twhitaker

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Re: Pressure drop when carbonating my keg
« Reply #1 on: December 07, 2016, 09:37:01 PM »
You need to leave the valve open. It will absorb pressure. I use one gas ball lock fitting for two kegs, need to bump up every 12 hours as they carbonate. Make sure you use soapy water on all your gas fittings so you dont lose all your gas if it leaks. Froth up the soap and brush on with a paint brush; examine all connections for growing bubbles. These are leaks, fix them if any .  Carbonation: Give it 3 days if you arent impatient. Close gas, relieve keg pressure to about 10 psi. and try some. I use a small picnic tap line inside the kegerator for sampling. If not ready disconnect picnic line and pressure back up to 30 or so for another day. IF ready, leave at 10 -13 psi and connect draft lines. Make sure you dont expose picnic line to more than 13 or so psi. ( or your draft lines once conncected).
Eventually the beer will saturate with co2 and become foamy,after a few weeks. At this point I shut off gas, relieve keg pressure to 0. The beer will pressure the lines enough to dispense, and carbonation level will come down.  CHEERS
« Last Edit: December 07, 2016, 09:57:06 PM by twhitaker »
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Offline BlueWingPig

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Re: Pressure drop when carbonating my keg
« Reply #2 on: December 08, 2016, 04:28:28 AM »
I second what Twhitaker says.  Another thing is if your beer is in the refrigerator it will cool and absorb more CO2 because cold liquids hold more than warm ones.  I generally set my pressure at about 12# and just leave it on.  It can take 10-14 days with this method.

Offline jcech344

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Re: Pressure drop when carbonating my keg
« Reply #3 on: December 08, 2016, 07:13:53 AM »
I now have just discovered this morning that both the keg AND cylinder (5 lb) show 0 pressure!  I now assume that my pressure drop was due to a leak and I have emptied all the co2 into my basement :-\.  I checked for leaks with soapy water and found none.  ARGHH.  I have opened a window in the basement to get air in as it am concerned that the levels could be dangerous.

Offline jtoots

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Re: Pressure drop when carbonating my keg
« Reply #4 on: December 08, 2016, 07:22:04 AM »
I now have just discovered this morning that both the keg AND cylinder (5 lb) show 0 pressure!  I now assume that my pressure drop was due to a leak and I have emptied all the co2 into my basement :-\.  I checked for leaks with soapy water and found none.  ARGHH.  I have opened a window in the basement to get air in as it am concerned that the levels could be dangerous.

LOL welcome to the first days of kegging... I shared this experience big time.  Have no fear, once you find the leak(s) you'll be sitting pretty.  Make sure everything that screws tight in the system is really really tight.  Also, if you keep the valve open, the pressure will keep the keg lid tightly sealed.  I've found that once the pressure drops to very low leaks can come up more easily.  Also, it's great to have a bottle of keg lube handy.  I very rarely use it, but in a pinch it works wonders.

Offline Cheetos

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Re: Pressure drop when carbonating my keg
« Reply #5 on: December 08, 2016, 03:53:23 PM »
Bummer on the leak!  But it happens to all of us at some point.  And just to clarify were you trying to carbonate the beer at 70 degrees?

Offline jcech344

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Re: Pressure drop when carbonating my keg
« Reply #6 on: December 08, 2016, 07:59:12 PM »
Originally I was doing this in my basement and the temperature there is more like 65.  I have since taken it to my garage where tonight it will be closer to 38.  Having done that I still find I cannot hold the set pressure.  After an hour it reads 0 when I set it at 25.  There has to be a problem with the regulator as I have checked and re-checked all connections.

Offline jtoots

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Re: Pressure drop when carbonating my keg
« Reply #7 on: December 09, 2016, 07:25:33 AM »
Having done that I still find I cannot hold the set pressure.  After an hour it reads 0 when I set it at 25.  There has to be a problem with the regulator as I have checked and re-checked all connections.

The way you describe this it sounds like you're closing a valve between the tank and the keg during this hour.  The beer is absorbing the CO2, so the pressure on the keg side will drop.  This is normal.  As TW said, you need to keep the valves open.  Sorry if I'm misreading.

Offline Cheetos

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Re: Pressure drop when carbonating my keg
« Reply #8 on: December 09, 2016, 05:06:46 PM »
CO2 needs to be on while it is carbonating.  Also the beer needs to be cold to carbonate.

 

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