Fast-carbing a keg ?

I will be kegging this Saturday morning but have some friends coming over that night and thought it'd be great if I could get this carbed by the night. I've heard of people fast-carbing by shaking the keg and they say you can have it carbed within hours using this method. I've never done this, I usually just let it sit for a week, so I wanted to ask those of you who do this - what are your thoughts on this. Is it generally true that you can get the beer carbed this quick using this method. Also I've read somewhere that doing so may result in inconsistently carbed servings (like one pour would be carbed fine, next one flat). Does that happen to you when doing this ? Thanks

I force carb every keg. Chill the keg and the put the gas to it. Shake the heck out of it until it stops absorbing gas.
I can do it in less than an hour easy.

I'll get on my soapbox right now and start shouting: This is THE way to do it!
The laws of physics prevent you from over carbonating, so long as you use the charts, and it only takes 10-20 minutes of rocking a keg under your foot while you sit on homebrewtalk.

As to the inconsistently carbonated servings, this is not possible. Fluid dynamics and Pascal's law ensure that every beer exiting your keg will be equally carbonated assuming that serving pressure and temperature are not variable... and that the operator of the beer tap is not mentally challenged.

I concur! It's so easy a caveman could do it!

So can this be done at room temperature or do we need to have the beer fairly cold before it is done.

Higher liquid temperature require higher gas pressures to carbonate.. Cooling your beer will make it easier for the co2 to stay in solution.

Just thinking on doing it fast.

Straight to fermenter around 70F (20C), pressurize and rock for 15 minutes.
Stick in fridge until serving temperature
Reduce pressure to serving pressure.

Would that work, or would you be better off

Cooling beer in fermenter to around 40F (3C).
Keg, pressurize and rock for 15 minutes.
Stick in fridge and set to serving pressure.

Sorry if the temperatures are a little off, I work with Celsius not Fahrenheit.

You can carbonate it at whatever temperature you would like. My thought process is like this:

Beer comes out of fermenter and goes into keg.
I want to drink beer, like, yesterday.
If I carbonate now, I can "forget about it" in the fridge while it comes down to temp.
I will then, likely, be sidetracked by something. It's fully carbed so whether it sits in the fridge for 12 hours or 16 hours doesn't matter, it's ready to go!

Also, there are two pseudo-bennies that come along with carbonating before chilling. Not that there is anything wrong with chilling first, it's just that: If you are in a rush and the party that you brewed the beer for is tomorrow, I would rather sample warm carbonated beer now and determine if everything tastes okay before day-of-party. Secondly, and the scenario is similar, if you are rushing to get into bottles so that you can send some cases down to a party in Madison (Go Bucky) that is tomorrow, it can now be done by saving the (typical) 12 hours of chilling time... You know... If you HAVE to... Since bottling room temp beer is a foam nightmare. (But can be done with patience and cold bottles)

Blah blah blah, this is just my ridiculous rationale. Realistically, if you can afford the patience and time, the "best" way to do it would probably be to chill then carbonate and that is really only for one silly reason: The gauges on your regulator are most accurate in the center (noon) position. Assuming that you have 30 psi gauges, you would get your most ACCURATE carbonation for your average beer when carbonating around 40F

Oh, and (I'm really rambling this morning, when is the coffee going to kick in?) one minor correction to your above process. "Rock for 15 minutes" should be a generalization. In reality, you will "rock until you no longer hear the regulator humming, no longer hear bubbling inside the keg, and quite possibly have beer visible inside your CO2 line."

Cheers!

I generally go the slow and steady method over 2-3 weeks. In the past I've on a couple of occasions cranked the pressure and or agitated the keg to speed it up -- they ended up with a nasty carbonic bite though which took 2-3 weeks to dissipate. Ironic? I may just be sensitive to it but the bite was horrid to my palette and I couldn't drink the beer until it faded.

Listen, advice is sometimes like ********, " everyone has one, and they all stink!" Chill your beer before you force carbonate, it will absorb way more co2 when it's cold. You need to chill before drinking anyway! So..,, good luck!

Was thinking that route anyway. You will use less gas and in reality you will be drinking it in the same amount of time anyway.

I guess the only time that becomes hard is if you have no where to store it to get it cold before you force carb it (fridge currently has a keg in it).

Just to be clear, it takes the same amount of gas to hit the same carbonation level, regardless of temperature.

But the headspace needs more CO2? I understand that the same amount of gas will be absorbed but it will need more gas in the keg for that to happen.

I could be wrong and please let me know if I am.

Are your friends beer snobs? Or drinking to get a buzz? Beer snobs will detect every flaw in you beer. If so, chill your beer then put it on gas. If it tastes good and is carbed to your expectations and you are proud of it, then serve. If it is not ready, do not serve. If your friends want a buzz, buy something for them. (or they can BYOB) Reserve your brew and serve when ready.

Personally, i treat serving like and interview. You only make one impression.

You can also chill, hook gas up to the bev out line, and fill/purge repeatedly. Wastes gas and drives off some of the aroma, but bubbling gas through works well.

Shaking works well, but you may end up with excessive foaming. Sediment shouldn't be a huge concern - you're not kegging for long enough that it'd drop out (but chilling first may lead to clearer beer).

It'll definitely carb faster chilled. As other folks have said, you'll need a lot more pressure to get the same amount to absorb.

Lastly, you're probably going to way over-carb (better then flat). If the beer has a nasty acidic aftertaste and is chilled, you can let all the pressure off and then set it a few PSI lower then you need. It won't solve the problem, but it'll help. Carbonic acid is 100% related to the amount of CO2 in your beer - reduce carbonation and it will address the issue.

Good Luck!

I just tried this method, worked pretty good.

5 gallons in a 5 gallon keg should keep the headspace pretty minimal. I assume that you would then chill the beer before actually drinking or serving it. (Yes, when I occasionally am forced to bottle from a warm keg I do use more CO2 to push the beer).

And to repeat: if you use the chart, accurately measure your temperature and your regulator gauge works properly- then you cannot over-carbonate using the agitation method. The laws of physics simply will not let you.http://www.kegoutlet.com/media/uploads_ckeditor/Carbonatin-Chart.jpg