Keg Force Carbing Methods Illustrated

[IPAAAA]

How long does it usually take for the beer to clear in the keg?

 

[infection]

This is not a science journal. It's more like a bunch of homebrewers shooting the crap at a pub and this graph is like something I'd draw on a napkin to compare the approximate absorption rates of the various carb methods.

Bingo!....we are not here studying for a physics test.....we are just a bunch of homebrewers sharing methods and techniques on carbing our kegged brew, and posting our successes and failures so others can learn

 

[HoppedIPA]

For me so far normally by the 4th pint its as clear as it going to get which is pretty clear so far.. and yes i do drink the non clear beer!
It may cause a bit of added flatulence.. haha

How long does it usually take for the beer to clear in the keg?

 

[IPAAAA]

Cool...definitely noticed the added odors leaking out of my body haha. Gonna do the gelatin next time I brew.

For me so far normally by the 4th pint its as clear as it going to get which is pretty clear so far.. and yes i do drink the non clear beer!
It may cause a bit of added flatulence.. haha

 

[ronstar55]

I kegged my first batch (oatmeal stout) yesterday - before I read this thread. I used instructions for force carbonating that came with my kegerator. I racked the beer and put it the kegerator overnight. Then I hit it with 30lbs, took off the gas and rolled it for 10 minutes. Let it sit a few hours (CO2 was disconnected ), then bled off CO2, set at 12lbs, and tapped a glass. It was ok, but later last night my next glass seemed flat.

From now on I'll use the steps mentioned in this thread.

This thread suggests that my stout will eventually carb up over a week or 2 leaving it at 12lbs.

I have 2 kegs, one bottle of CO2, one regulator with 2 lines. I have another batch in the fermenter now.

If I want to boost carb the 2nd batch, it looks like I'll have to shut the gas off my first keg if I want to boost my 2nd at 30lbs for a day or 2?

It seems to make sense to just set it and forget it since I only have one regulator for 2 kegs so that I won't have to take the first keg off gas.

 

[ragweed]

I've had a couple kegs on at ~15PSI and cold (35F) for two full days now, and have shaken them a couple times. I'd like the beer to be carbed enough to be drinkable tomorrow night, any chance of that happening?

From reading this I guess I need to up the PSI now (~30PSI), stop shaking them, and then a few hours (how many?) before serving lower the PSI and bleed off/release the extra pressure in the keg. Sound like my best bet?

Thanks for any help.

 

[HoppedIPA]

I having no data... what i would try if it was mine is yes turn it up to 25psi shake it till you hear it stop burbling... I bet most people dont force carb with the gas connected to the liquid side, like i do so there wouldnt be any brubling... hmmmm See i connect another black=liquid connector to my gas for carbing to let it burble through the liquid i do this for a few minutes. then i stop shaking and then when that stops burbling i turn it down.. to 20 or so for alittle while normally 24 hours or so.. The worst thing that can happen is it over carbs and you get alot of foam right?
Dont take me word for it..

I've had a couple kegs on at ~15PSI and cold (35F) for two full days now, and have shaken them a couple times. I'd like the beer to be carbed enough to be drinkable tomorrow night, any chance of that happening?

From reading this I guess I need to up the PSI now (~30PSI), stop shaking them, and then a few hours (how many?) before serving lower the PSI and bleed off/release the extra pressure in the keg. Sound like my best bet?

Thanks for any help.

 

[Frodo]

The question your addressing with your graph is, "How fast is the carbonation?", and your graph implies that the rate can be described by the mathematical model depicted in the graph, yet you have no data to make such a conclusion. Consequently, the graph may be very misleading and not as helpful as you assert. I'm not saying you are wrong. I'm just saying you don't have the observational data to make such assertions.

Wow and I thought I could sometimes be an *******. Since when doesn't experience count for anything? He stated upfront, at least twice as I recall within the first couple of posts that the graph was something thrown together to help others who were asking a lot of questions about kegging.... Just like I was about to before I read this thread and saw the discussion.

Thanks Bobby for the awesome graph and all the thorough explanation throughout this thread, as well as all the others who have contributed their experiences and knowledge. Also, nice analogy about this forum being like a bunch of homebrewers discussing topics at a pub, and sketching on napkins.

 

[Bobby_M]

Thanks for having my back. Some people like to drag their ass on your light carpets when they have monkeybutt.

 

[fdb16]

I was trying to read through the post but my eyes started going cross eyed. I see in the beginning that you can over carb by putting it at 30 and leaving too long. As far as set and forget, wouldn't set and rock to force the co2 into the beer be as effective? Wouldn't the beer only accept as much pressure as what you set the regulator to? I usually just set and forget but need something done quick and don't want to over carb. Anyone have experience with this method? I apologize if this has been addressed, I just couldn't read anymore. Cheers!

 

[Bobby_M]

Yes, you can shake at chart pressure forever and it won't overcarb but it's a little impractical because you have to sit there and do it for a while, or come back to it regularly. I really have no idea how many times you'd have to do it for or how much time it shaves, but rigging it into a huge paint shaker would be awesome.

 

[fdb16]

FYI: i set it to 11 psi and just rocked for about 30 min with my feet while watching football on the couch. I got tired and let it sit for awhile, went back at it an hour later for about 40 min. Decided enough was enough and let it sit in the kegerator. I just took a pull about 1 hr after rocking to see where I am at, and all looks good. Well carbed, probably not to perfection, but well enough. My plan was to rock until the beer stopped taking on gas, that never happened. Next item to brewery list, supersized paint shaker! (better plan on better timing)

 

[Frodo]

Sounds like a good upper body workout too!

 

[BrokenDog]

I will be kegging my first beer in the next week or two and want to have this page for reference, thanks.

 

[Hugh_Jass]

Bobby,
quick question for you:

when force carbing, we're concerned the liquids ability to absorb CO2 at given temps. why do the same parameters not apply when naturally carbing a bottle or even a corny?

When I look at naturally carbing charts, there's no compensation for varying temps.

Thought of that the other day and couldn't come up with an answer.

Thanks

 

[Bobby_M]

Great question. The answer seems obvious to me but I'm having a hard time writing it out but here's a go at it.

When sugar priming or naturally carbing, you're adding a fixed amount of additional CO2 (potential) to a sealed vessel. The amount of CO2 the sugar/yeast produces is an additive effect there. If you start with 1.2 volumes and the sugar will add 1.7 volumes, you have 2.9 volumes total. You really can't change it once you put the cap on.

When you force carb with CO2, you're achieving total carbonation by a fixed pressure at a certain temp. If you set the pressure (based on the charts) to get to 2.5 volumes, it doesn't matter if you start at .9 volumes, or 1.3 volumes, or 2.4 volumes. It will always seek equilibrium at 2.5 volumes. The only thing that changes is how long it takes to get there.

Does that make sense?

 

[Hugh_Jass]

I'm still trying to wrap my Hugh_Jass head around this.

When you force carb with CO2, you're achieving total carbonation by a fixed pressure at a certain temp. If you set the pressure (based on the charts) to get to 2.5 volumes, it doesn't matter if you start at .9 volumes, or 1.3 volumes, or 2.4 volumes. It will always seek equilibrium at 2.5 volumes. The only thing that changes is how long it takes to get there.

so when force carbing, the CO2 dissolving into solution is dependent on pressure/temperature. The lower the temp, the less psi required to force the same volume of CO2 into the beer. I understand this.

When priming w/a certain amount of sugar, the amount of CO2 given off by adding a certain amount is sugar is known, and that CO2 will be all be contained within the container. This CO2 dissolved into the solution will be the same regardless of temp?

I'm still scratching my head a bit. More later. Thanks

 

[jgourd]

I'm still trying to wrap my Hugh_Jass head around this.



so when force carbing, the CO2 dissolving into solution is dependent on pressure/temperature. The lower the temp, the less psi required to force the same volume of CO2 into the beer. I understand this.

When priming w/a certain amount of sugar, the amount of CO2 given off by adding a certain amount is sugar is known, and that CO2 will be all be contained within the container. This CO2 dissolved into the solution will be the same regardless of temp?

I'm still scratching my head a bit. More later. Thanks

It has nowhere to go and once the head space is full, it will force itself into the beer regardless of temperature since the yeast will consume the sugar and produce CO2. Unless of course you have a loose cap.

 

[Bobby_M]

The added carbonation that happens from adding sugar back into the beer is pretty predictable based on how fermentable that sugar is. The only way you'd counteract its natural trajectory is to chill the bottle before it was done.

There was a whole debate on another thread about how the CO2 dissolves into the beer during bottle conditioning and the consensus is that the pressure of dissolved CO2 and the headspace pressure is pretty much at equilibrium at any given time, all the way up full carbonation. In other words, the headspace doesn't "get full" of CO2 and then dissolve in a stringent order like that.

The reason why the volumes of CO2, which is our measure of carbonation level, is fixed no matter what temp the bottle is at is because it's a closed system. The pressure increases as temperature does, but the number of CO2 molecules never changes.

 

[Frodo]

I had to look some of this up, AND I've been taking a couple pulls off my first kegged beer! (so the point is, don't take this as gospel since I'm kinda drunk). I'm just so excited to have pulled a couple beautiful pints that I feel I need to add something, whether it's good or not...

First off:

Volumes of CO2 = 1 Liter of CO2 gas per 1 Liter of Beer at STP.

STP is "Standard Temperature and Pressure". Standard Temperature is 0C (32F) and Standard Pressure is 1 atmosphere (14.7 psi aka the weight of earth's atmosphere at sea level). (I didn't realize I always had 14.7 psi pushing down on every inch of my head BTW... no wonder I can't fly, I'm pretty sure my head is more than 5" x 6", or 30 square inches... so I have 441 lbs pushing down on my head!!! Holy crap I'm surprised my neck doesn't snap). Anywho, back to the task at hand:

The only variables we're working with, given a particular volume of CO2 as chosen by style if you so desire, are Temperature and Pressure.

So in a bottle with carbonating sugar and a sealed cap, if the yeast do their job they slowly create CO2 over the course of a week or 3, and they make the corn sugar you added at bottling time into ethanol and CO2. In other words there will be a steady BUILDUP OF PRESSURE while the sugar is converted. So the reason a natural carb chart is important for bottling is that you need to know precisely how much CO2 is already dissolved (created during fermentation) and how much additional you'll need to add during bottling. That's why the temp/carb charts are so important for bottle carbing.

With kegging, you apply a constant pressure from the CO2 canister through the regulator. It's not a closed system. The temp makes a difference now, not in determining whether the yeast will ferment the sugar but in how much CO2 will dissolve under the CONSTANT PRESSURE you're applying. That's where the chart comes in to tell you how many volumes CO2 will be absorbed under a given pressure of CO2.

 

[BigB]

I haven't read more than 7 pages so far, but man is this a great, informative thread! Thanks Bobby! I'm considering converting fridge and this thread, in only 7 pages, answered the questions I had thus far.

 

[johnnyk]

I've been looking everywhere for something like this. Great explanation.

I have my cornies, CO2 gas etc and i'm going to put my beer in my keg tonight and kept coming across so many different ways to carbonate the beer I was getting confused!

This is great and I will hopefully be able to do it easy enough now.

Cheers,

 

[Jknapp]

Any adjustments to make to the process if kegging in 3 gal cornies?

I'm thinking the smaller keg affects the headspace to beer ratio.

 

[proudportland]

I am new to kegging and was wondering what you mean when you say 2 vol.co2. Also should I be force carving inside or outside the kegorator? Thank you for reading. brew on my friends brew on

 

[Bobby_M]

There really is no need to account for smaller sized kegs or smaller volumes of beer.

 

[WolfExile386]

Well First off as a n00b to home brewing and kegging (I have been planning out all my first-time purchases for about the last 1-2 weeks, and have found this site to be a sanity saver) I'd like to thank Bobby and all the other experienced folks here for trying to keep this as understandable as possible while still trying to illustrate the important points. My plan is to jump kind of head first into this new planned hobby and tackle both brewing and kegging my first time out as my SWMBO does not want to have to deal with all the bottles. I was very intimidated by the thought of kegging my own beer, but after making it thru all 30 pages I am much more confident. Thank you all again, I'm sure I will have some questions once it comes time to actually tackle the task ahead of me as I still need to order all my supplies, but this thread alone proves to me that I have nothing to worry about as you are all so helpful. I cant wait to start and I'll keep everyone posted on how the Virgin batch comes along...till then Cheers!

 

[nolnacsm]

I'm brand new, and I majored in History & English. So, I have trouble understanding volumes to PSI. I get the concept of beer absorbing CO2 to create carbonation (head), and I get that it happens naturally over time.

One of my (many) problems is that I use a 2nd hand Bev Air that I got for a steal. I installed a double tower and have had 2 commercials 1/6 or 1/4 on tap for about a year - at about 10-12 PSI. Now that I've added a batch of homebrew (german ale), I'm having trouble figuring out how to strike an even PSI keel so all the kegs get along in there.

Should I just set it at 8 PSI and forget it?

 

[Frodo]

... post that was being responded to was deleted...

 

[dstebor]

Thanks for this post very informative, i'm planning on putting my barleywine in keg tomorrow after two weeks dry hopping in secondary.

 

[AtlasBrew]

New to kegging as well, thanks Bobby for the great info!