Working on my first kegged homebrew. I hooked up the CO2 yesterday and put it in the fridge. The pressure on the gauges dropped from 700 to 500 on one gauge and from 14 to around 5 or so on the other gauge. I had read there would be a fluctuation in pressure. Is this the normal amount?
CO2 in fridge and pressure drops
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yeah, that'll happen. it's hard to read the gauge if it's in the fridge. mine always sits in the red after i put it in the kegerator.
How long does it typically take to carbonate?
Before I put it in the fridge, I forced carbed by cranking the pressure to 25 and shaking the keg for a couple minutes. Then, I reduced the pressure to 14 and put in the fridge. Its been a little over a day now. It has a little carbonation to it but definitely needs more. Is this going to take several days?
Before I put it in the fridge, I forced carbed by cranking the pressure to 25 and shaking the keg for a couple minutes. Then, I reduced the pressure to 14 and put in the fridge. Its been a little over a day now. It has a little carbonation to it but definitely needs more. Is this going to take several days?
Since the tank pressure gauge inside the fridge is now skewed, I'm assuming I need to disconnect it from the keg, take it out of the fridge and let it adjust to room temp, then adjust the setting and rehook up?
No.
Cover that "high pressure gauge" (which is useless) with duct tape and pretend it's not there.
Then, keep the beer at 12 psi for a week or two. It should be well carbed by then. I'm not a fan of shaking the beer at a higher pressure, but it shouldn't matter too much in a week or so.
Daybis
Well-Known Member
The pressure inside the tank is at that lower pressure now. The temperatures of the gas inside the tank is now colder so it exerts less pressure. Look here: http://en.wikipedia.org/wiki/Ideal_gas_law You don't need to disconnect everything in the keg. You still have the same amount of CO2 and everything is fine. My tank pressure always sits between the red and white when it's in the fridge. I always set my pressure at 10 - 12 psi and I leave it for a week or so.
johnsonbrew
Well-Known Member
Simialar expericence to mine the first time I kegged. My buddy works for the company that supplies CO2 and he said that when you cool your CO2 tank, because it is a "liquid" gas that everytime it cools below 50 degrees you look pressure in your tank. My gauges did the same, dropped a pretty good amount.
As far as force carbing is concerned. On my first beer I only had 48 hours before the first taste test. I did the 30 psi and rolled the keg for 5-7 minutes and tested it. It looked perfect and tasted good too. I put it back in the refrigerator for two more days at about 15 psi and just let it sit. When I served the beer, the first glass was pretty foamy but after it settling and getting the pour pressure right (about 4-5 psi) the beer to flowing perfectly and the keg was empty by the end of the night. I am going to do the same for this next beer because I wanted a longer secondary fermentation but it will be sitting for a few more days. The longer you let it sit in your keg, the happier you will be.
As far as force carbing is concerned. On my first beer I only had 48 hours before the first taste test. I did the 30 psi and rolled the keg for 5-7 minutes and tested it. It looked perfect and tasted good too. I put it back in the refrigerator for two more days at about 15 psi and just let it sit. When I served the beer, the first glass was pretty foamy but after it settling and getting the pour pressure right (about 4-5 psi) the beer to flowing perfectly and the keg was empty by the end of the night. I am going to do the same for this next beer because I wanted a longer secondary fermentation but it will be sitting for a few more days. The longer you let it sit in your keg, the happier you will be.
^this works like a charm.
exactly, once that tank's cold, the gauge is worthless for the most part.
i agree that the shaking thing isn't the best idea. i've heard some things lately here on the forums that made me glad i decided not to use that method when i first got into kegging. i do like to keep the pressure around 30 or so for the first 48 hours after i turn the gas on, then after that i back it off to serving pressure. (10-12 psi) and a couple days later it's carbed up and tasty.
Actually, the high pressure gauge will still read accurately at fridge temps. It will just read lower due to the pressure/temperature relationship of CO2 in a liquid/vapor state, but it still doesn't tell you anything about how much liquid CO2 is left in the tank.
CO2 in a liquid/vapor state has a direct pressure/temperature relationship, as can be seen in the chart below. The pressure will stay the same, at a given temperature, until all the liquid has been vaporized. Once only vapor exists, the pressure in the tank will drop rapidly. The only way to know for sure how much liquid CO2 is left in the tank is to weigh the tank, and subtract the tare weight that's stamped on the side of the tank.
Also, fwiw, When you keep the CO2 tank in the fridge the elastomer that is used for the regulator's diaphragm will be slower to respond to changes in output pressure when it's cold.
For example. If you have the regulator in the fridge and set to 10 psi and then you change the output pressure to 12psi, you may find that when you come back in a couple of hours that the new output pressure may be 15 psi. This "creeping" effect is due to the cold temps effecting the diaphragm. I've learned to compensate for the "creeping" effect by setting the new output pressure just slightly lower than my intended pressure. It will then creep up to my new setting after some time. Usually not very long.
CO2 in a liquid/vapor state has a direct pressure/temperature relationship, as can be seen in the chart below. The pressure will stay the same, at a given temperature, until all the liquid has been vaporized. Once only vapor exists, the pressure in the tank will drop rapidly. The only way to know for sure how much liquid CO2 is left in the tank is to weigh the tank, and subtract the tare weight that's stamped on the side of the tank.
Also, fwiw, When you keep the CO2 tank in the fridge the elastomer that is used for the regulator's diaphragm will be slower to respond to changes in output pressure when it's cold.
For example. If you have the regulator in the fridge and set to 10 psi and then you change the output pressure to 12psi, you may find that when you come back in a couple of hours that the new output pressure may be 15 psi. This "creeping" effect is due to the cold temps effecting the diaphragm. I've learned to compensate for the "creeping" effect by setting the new output pressure just slightly lower than my intended pressure. It will then creep up to my new setting after some time. Usually not very long.
postal_penguin
Well-Known Member
The pressure gauge works fine at refrigerator temps. What the dial says is what the PSI is being dispensed at.
we're referring to the gauge that reads tank volume, not keg pressure. the volume gauge will read low when it's cold.
Right. And then empty when it's empty.
In other words, it'll show "fill tank, 500 psi" from the day you fill it until about 1/2 hour before it's completely empty.
The reason is actual simple- it's a liquid dispensed as a gas. So any pressure registers the same as "fill tank". But it'll go from 500 psi to 0 almost instantly when it's empty!
The only way to see how much gas you have left is to weigh the tank. The tare weight is stamped on the tank, so you just subtract the current weight minus the tare weight to get the amount of gas left.
exactly. i go by the weight and keep a full tank on hand so when that tank mysteriously stops feeding co2, i have one to hook up right away. the volume gauge drops fast when the tank starts to get low, a full tank reads ~600 in my kegerator, once it reads below 200 psi, it bottoms out quickly.
i dig the new avatar, Yoop.... much nicer to look at than Lidstrom (or Holmstrom or whoeverstrom), IMO.
12 psi via the temp reading while in the fridge?
So mine is now at 5 or so, should I turn up to 12?
Yes.
gyropilot1
Well-Known Member
But when you yank it to 30 psi and then drop it to 12. where the other 18 lbs went since you are adjustion the input not releasing the presure
novaraz
Active Member
In the beer! As in, the gas at 30 PSI in the headspace dissolves into your beer. If the beer is already saturated with CO2, the gauge will stay at 30 PSI and you'll have over-carbed your batch.
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