Keg Force Carbing Methods Illustrated

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Yeah I also did something similar with shaking the keg at 30 psi for a few minutes, but without waiting any time for the keg to rest on high pressure. However, now several hours later having let the keg sit quietly in the fridge off gas, I am getting 95% foam 5% liquid, and the beer itself tastes FLAT.

I have 6' of 3/16" line and am dispensing at 12 psi. There is considerable foam in the beer line -- would that convert the beer coming out of the keg into foam if I can't clear it out, or is something else going on?

How in the heck could it be overcarbed, yet taste entirely flat??

All that foam is all the carbonation. It's like if you take any carbed beer and shake it in the glass, it will foam up and the beer will be flatter due to loosing the gas into the foam.

Did you vent your keg before trying to serve it off the gas? If you try and serve it at 30 psi with only 6 ft of tubing it will come out of the tap too fast causing it to be too turbulent causing only foam. Try venting it then hooking it up to the gas at 12 psi.
 
For whatever it's worth, I am reverting to the shake method. The only reason is that I think it's more time efficient. Screw ups can be fixed in less time than any other method. This is just my own preference. Great post BobbyM.
 
I don't know if this has been covered here or somewhere else, but with the chart, how long does it take to reach the co2 volume at the particular temperature based on the psi?
 
I too overcarbed my beer. I need to purge the tank of CO2 and reduce the PSI. Is there an estimate of how many times I need to purge the tank of gas? My guess is it depends on how much I am over carbed but wanted to check.

So the theory is that if I set the regulator for 10 PSIG for 2 weeks at 40 degrees F it will be at approx 2.3volumes? Will it stay at that if I leave it at 10 PSIG or will it continue to absorb more gas? (assuming I leave it at a constant Temp).
 
Your theory is correct. The temp/pressure chart is a long term fixed equilibrium. Once it hits the 2.3 volumes, it will stay there. I'm sure there are formulas that say how many times you'd have to vent the headpressure to reduce volumes, but it would certainly be based on temp, beer volume, headspace volume and current volumes of co2 dissolved. Way too much to worry about. Just trial and error should work.

Note, if you need to downgrade your carbonation level, it's best to leave the gas diconnected as your going through the venting process. It's silly to apply gas to a headspace that you're just going to vent all over again.
 
Yeah I didn't think that one through when I typed that huh? LOL!




Your theory is correct. The temp/pressure chart is a long term fixed equilibrium. Once it hits the 2.3 volumes, it will stay there. I'm sure there are formulas that say how many times you'd have to vent the headpressure to reduce volumes, but it would certainly be based on temp, beer volume, headspace volume and current volumes of co2 dissolved. Way too much to worry about. Just trial and error should work.

Note, if you need to downgrade your carbonation level, it's best to leave the gas diconnected as your going through the venting process. It's silly to apply gas to a headspace that you're just going to vent all over again.
 
Bobby,

I posted another thread yesturday but reaally did not get the answer I was looking for, it seems like you really have a handle on this kegging thing, I racked from the primary to my keg with 1/3 cup of priming sugar, purged it with about 5 or 10 lbs and let it sit at room temp for 3.5 weeks, i put it in the fridge on Monday and tapped it last night and its flat, tastes great but flat, i turned up the lbs to 12 and just tryed it again and still flat.

When I tapped it it still had pressure because I hooked up the beer line first, but I guess the seals could have leaked.

What is the best choice at this point, 30 lbs for a day? Shake the keg at 30?
Please give me some ideas if you can.







I'm not sure if there's some magic math that can be done to figure out exactly how much of an initial pressure shot it would take at room temp to have a beer fully carbed without any additional constant gas. I've tried playing with the numbers but it made my head hurt so I gave up. If I understand it properly, you have to compare the headspace volume to the entire keg volume to know how the pressure will drop.

10psi? Heck no. That's 10psi in a headspace 1/10th the size of the whole keg. Once it absorbs into the beer, you get like 1 psi equilibrium which is .75 volumes. Let's try 40psi. 1/10th is 4 psi so room temp would be .9 volumes.... Hey, if it's a bitter, you might be close now.

If you're shooting for 2 volumes, it would take 20 psi equilibrium at room temp, which is about 200 psi in a 1/10th headspace.

Athough it doesn't get me all the way there, I still hit my kegs with 40psi before I tuck them into the basement for a short warm aging period (If I have enough supply flowing already of course). I'd rather start with .9 volumes when it hits the kegerator than 0 volumes.
 
If you're in a hurry to drink it, try 30psi overnight if the beer is cold. After 24 hours, disconnect the gas, reset the regulator to 12psi, pull the purge valve on the keg for a second or two and reconnect the gas disconnect. The 30psi for 24 hours might not get you 100% there, but it will continue to carb at the 12psi setting also. You just don't want to overcarb because it's a pain to offgas it. I suspect you did have a leak at some point.
 
Bobby,

Thanks for the reply, I am will do that and see how it goes.

So what is the best way to do this? I did have new seals on the keg, should have I purged it with 30 psi at the beginning and that might have sealed it better? I really wanted it to just do the natual carb thing, just like a big bottle,
 
Honestly, I've never sugar primed a keg so I'm not the guy to ask. However, I know that keg lube on the main Oring is one way of ensuring a better seal. I've read that a lot of people hit it with 20psi to seat the lid before tucking it away to carb.
 
Bobby,

Well I turned it to 30 psi for 23 hours and it turned out perfect, how simple a fix, I thank you so much for the insight, now my next decsion is to figure out how I will do it in the future, i am thinking that I will just age it and then do the same thing, 30 psi on a chilled keg for 24 hours and see if it is ok.


Thanks again,

Jeff
 
Your theory is correct. The temp/pressure chart is a long term fixed equilibrium. Once it hits the 2.3 volumes, it will stay there. I'm sure there are formulas that say how many times you'd have to vent the headpressure to reduce volumes, but it would certainly be based on temp, beer volume, headspace volume and current volumes of co2 dissolved. Way too much to worry about. Just trial and error should work.

Note, if you need to downgrade your carbonation level, it's best to leave the gas diconnected as your going through the venting process. It's silly to apply gas to a headspace that you're just going to vent all over again.

Ok, this is the question I asked myself yesterday. Of course I couldn't come up with an answer, because I didn't know it, that's why I asked myself in the first place!

So, let's say that I carb my beer with 20 lbs of pressure for a short time, then drop the keg pressure to serving pressure, say 6 lbs (cause I haven't looked it up yet). You're saying that the beer will stay carbed just like it was when I dropped the pressure on the keg? It wont start losing carbonation over time? Or if so, how much time are we talking?

Also, where can I find a digital copy of that carb chart? I want to keep a copy in Excel format, and maybe print a nice one off to put on the kegerator... Plus a chart with different beer styles and their proper carb levels.
 
So heres my situation. I cranked my reg to 30psi, gas in, rolled in my lap for a few minutes, bled it off, back in the fridge, pulled a "sample", pulled a little more "sample", then 20psi overnight, and I just came to work leaving it at about 12 (sampled a bit more this morning). I figured this would be a reasonable combo of the burst and set and forget methods. I think it will be good. The sample this morning had alot of foam (since it was at 20psi on a 5' hose), but I could tell the beer wasn't done carbing yet so I think I'm in good shape. Any suggestions?
Thanks
 
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The hardest thing is recognizing when a beer is really carbonated vs. when a beer has simply been blown through a serving line under intense pressure. They both have a foamy head but only one is a result of CO2 coming out of solution that was originally dissolved in the beer.

I can make a few more true statements that might also help. There are a few things that increase the speed at which CO2 will dissolve in the beer (the carbonation process).


1. Higher pressure applied to the headspace. We know that based on the charts, a higher pressure will ultimately end up at a carbonation level well higher. Even if you target is 2 volumes, setting the pressure so that it would ultimately reach 4 volumes will get you to 2 volumes quicker. BUT!!!! you'll never really know when to stop and purge. It's a guess.

2. More CO2 to beer surface area. In a typical corny, the contact between beer and co2 is about 28 square inches (the area of the surface of the beer). That's a pretty small area give 5 gallons of beer. The tricks to increasing surface area is physical agitation and gas diffusion. When you agitate the keg, it makes the headspace of co2 turn into a million bubbles immersed in the beer presents a much larger surface area than 28sqin. You can also achieve a similar effect by putting a stainless stone on the incoming gas and having it immersed in the beer. Using either of these surface area techniques with the pressure from the chart is the ONLY way to be 100% sure that you are not overcarbing in the process.

Of course, you can do a combination of these to get there faster but the odds of overdoing are increased.

Just like in my first post, the only time I'd agree with speeding carbonation is if the beer has already been properly aged already. If not, the tried and true set and forget method accomplishes a predictable carb level and aging in one process.

I also don't want people to think that just because they increase pressure and agitate the keg that carbonation is absolutely instantaneous. Just for discussion's sake, let's say you have a 35F keg of beer and you raise the pressure to 30psi. Given the chart, with about 2-3 weeks wait, the beer will achieve 4.5 volumes of co2. Maybe you really want 2 volumes but you're trying to get it done faster. Is it 2 days? 3 days? I'm not sure, but it's definitely not 2 weeks. Now, same example with temp/pressure but let's say you shake the crap out of the keg at the same time for 5 minutes. How many volumes are you at immediately after? Who knows, it could be 2 volumes.

If you're into being exactly to style and want reasonable accuracy on carb levels, stick with chart and wait. If you really want to hurry but still be reasonably accurate, use the speed methods and then get a bleeder valve with a pressure gauge on it. How's what work?

If you have a keg sitting around that is in some state of fixed carbonation but you don't know what that is, you can put a pressure gauge on it to find out. The caveat is that it has to be a fixed carb level where the CO2 dissolved in the beer is at equilibrium with the pressure in the headspace. If that is met, you can read the head pressure, measure the beer temp and find the volumes on the chart.
 
What about the technique of putting the gas onto the Beer Out line so the co2 can bubble up through the beer? Any do this? I read it on another site.
 
It's just not enough surface area to make any difference. The alternative is to put a diffusion stone on a piece of tubing in the gas in port, but that's another sanitation concern for little gain. If you want to hurry, increasing the pressure for 2 days or agitating the keg for a few minutes is just as easy. I do know that a few people around here have played with a special corny lid that has an aux gas in port where the pressure release valve normally goes and that had a tube with stone on it. You'd put that on for carbing, then replace with a normal lid later.
 
Let me get this straight.

For burst

1. Set bottle to 3x desired psi.
2. Wait 48-72 hours.
3. Then you say "purge", does this mean I should disconnect and bleed all the gas out of the keg?
4. Then I would assume once 3 was complete I would put it back onto the desired pressure and wait.
 
ok, i've got a question that touches on a lot of things covered, but i want to make sure i do it right...

kegged a beer and hit it with 10-15psi every couple days for two weeks at room temperature. then hit is with 30psi and agitated it, again at room temperature. i put it into a fridge a couple days later at 38degrees. a week later i let out all the co2 and poured my first glass. a decent amount of foam, but the beer was flat.

did the co2 not take well to the beer because it was warmer? should i hit it with a constant 30psi for 24 hours in the fridge for better results? after i keep it at 30 for a day, should i purge all the gas again, and reset the co2 closer to a desired psi, like 10ish, depending on the carb chart? i'm hoping to have it right by a party on saturday. i've got 5 days...
 
My initial post and the pressures/times listed were assuming cold beer. Hitting a warm keg with 10-15psi in short bursts just about does nothing. Well, let's say that 10psi applied constantly for 2 weeks would end up at 1.21 volumes. So, I'd disregard the lower pressure activity you performed.

30psi at room temp under agitation could get you to 2 volumes of CO2, but I think it would take a couple rounds of shaking over the course of a few minutes until no more Co2 would flow in.

Once you get the beer cold, the CO2 that has been previously dissolved in should stay in during a pour if your lines are balanced well. That's where I'd start troubleshooting. How long is your serving line and what's the inside diameter?
 
My initial post and the pressures/times listed were assuming cold beer. Hitting a warm keg with 10-15psi in short bursts just about does nothing. Well, let's say that 10psi applied constantly for 2 weeks would end up at 1.21 volumes. So, I'd disregard the lower pressure activity you performed.

30psi at room temp under agitation could get you to 2 volumes of CO2, but I think it would take a couple rounds of shaking over the course of a few minutes until no more Co2 would flow in.

Once you get the beer cold, the CO2 that has been previously dissolved in should stay in during a pour if your lines are balanced well. That's where I'd start troubleshooting. How long is your serving line and what's the inside diameter?
it seems like getting the beer cold first made a huge difference. i kegged my first beer before i got my freezer and i ended up with all those problems. i kegged my second after i got the freezer and the process went a lot more smoothly. i basically ended up carbing the first (warmly carbed) beer again from scratch at 30psi using consensus ideas from this thread, this time cold, and it's coming up much closer to where i want it to be.
 
Well think of it this way, if you go with 30psi when cold, that's approximately 3x the recommended "set and forget" pressure for cold beer. If you do the same thing with the beer at room temp, 3x the pressure is closer to 90psi which is dangerous.
 
Well think of it this way, if you go with 30psi when cold, that's approximately 3x the recommended "set and forget" pressure for cold beer. If you do the same thing with the beer at room temp, 3x the pressure is closer to 90psi which is dangerous.

yeah, that makes sense. when i first started carbing at room temp, i was doing it with advice from a friend and didn't really do much research own my own beforehand. i was just taking his advice for it all. knowing that cold beer absorbs CO2 a ton better makes a world of difference. i'm glad this thread has been stickied. haha.
 
hey I am new here, been reading alot on force carbing. I just kegged for 2nd time and tied a way that worked very well for me. I looked up the correct serving pressure for my style of beer, chilled the keg down to serving temp and applied the 10lb pressure while rocking the keg for 20 to 30 minutes then put back in fridge with the co2 at the same 10lb pressure. I let it sit for 2 hrs and had nice carbination. I was surprised as my 1st round at force carb. I way over did it. It takes a bit longer this way but you don't overcarb. Has anyone else done it that way. I found a post on another webpage that said to try this and it worked great for me.
 
I just ordered my two keg kegging setup with a dual body regulator from keg connections yesterday, this post has been extremely informative for me as I mentally prepare for the shift from all bottling to mostly kegging.

I do have one question though - I don't have a kegerator yet and planned to store my serving temp kegs in a normal upright fridge, but lying on their side. I obviously don't plan to dispense that way, my thought was to pull the keg out and dispense each beer, or for gatherings put the chilled keg in a tub of ice. I'm just wondering, can I keep it the keg on gas or under pressure while lying on its side, or will the gas that may get into the dip tube cause issues when I go to serve?

I do have a kegerator lined up, but it may take a month or so to get it. My kegging equipment will likely take 2 weeks to get shipped and arrive, and I may let the beer age before gassing it anyways so I may have the kegerator in time -- but assuming I don't, what do you think about lying on its side in a normal fridge?

I apologize if this question has been asked and answered multiple times elsewhere -- this seemed like the right place to ask.
 
I have a few questions-

Does anyone have a step-by-step guide on how to keg?

So, I rack to my keg. Now I want to cool before force-carbing. But I also want it on a blanket of CO2. So do I rack, seal, blast with 15lb, cool, then proceed with carb?
 
Sanitize.
Flood with a bit of CO2.
Rack beer in.
Seal
20 psi of CO2 applied for a second. Vent. Pressurize to 20psi.

Now you can either store it warm for a while, leave it on serving pressure while you chill it, or chill it and perform a rapid carbonation method.
 
Thanks Bobby!

So, if I had two weeks to carb, I would take my 20psi keg, put it in the fridge, then when it gets to temp pressurize to serving pressure then just leave it alone? I'm assuming taking a 20psi keg at room temp and putting it in the fridge will leave me with a very low pressure keg, is this accurate?
 
Yes, assuming you mean that you have the gas disconnected between room temp and the chill down, the pressure will drop quite a bit so you can just set the reg to serving and let it go for 2 weeks. My tip is to leave the serving line off the keg that whole time too otherwise you'll be down a gallon by the time the thing is carbed up.
 
leave the "serving line" off.....leave the gas line off?

so chill it, pressurize to, lets say, 12 psi, then disconnect the gas?

why would i be down a gallon of gas, just leakage?
 
No, I really meant serving line. There's something about having easy access to the contents of the keg (like the faucet) that makes a brewer regularly "test it out" every day during the carbonation process. You figure, it's just an ounce or two. Bam.. two weeks later the keg is light.
 
hahaha, I kind of thought that's what you meant.

i have a moderate amount of patience. plus both these kegs are for new years, so they aren't to be touched until then.

but, yeah.....good idea. thanks!
 
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