Dissolved CO2 is dissolved CO2 for our purposes, and the controlling factors are temperature, pressure, and time. You can only affect one of these, and that is time. Agitating the liquid exposes more of the liquid to the gas, thus making the CO2 mix into solution more rapidly. Shaking the beer doesn't do anything more than help speed the process along. Don't believe anyone that tells you they don't shake because it affects the beer. The important factors are temperature and pressure. Use the standard chart to find the volumes of CO2 you want, and get going! Also, all carbonation using CO2 under pressure is force carbonation, regardless of the speed you perform it at.
http://www.homebrew.com/pdfs/CO2chart.pdf
Use the carbonation chart at the link above, or use the same chart available in many places around the web. At the bottom of this page are more links for carbonation that might help. Don't make this tougher than it is, and don't try to re-invent the wheel, just follow the process and learn the rules to be happy!
The best way of carbonating your beer is to set the pressure and leave the beer alone in the fridge for a few weeks. That solves two issues. The first is nice even carbonation, and the more important one is proper conditioning. So many people don't let the beer condition properly and are in a hurry to carbonate and drink it. Both carbonation and conditioning can happen at the same time in the fridge ot kegerator, so patience is the best method, and it is nearly foolproof. (OK, it is only fool-resistant, they make better fools every day).
I just don't see why people have a problem with carbonating by the numbers, regardless of shaking (rapid force carb) or not (regular force carb).
As for the main question "how much CO2 is in my beer?" The answer is still simple by using the chart. For a given pressure at temperature, you have given volumes of CO2, with small variations not really measurable by human taste or feel. If you are carbonating your beer by a proper method where you know the temp and pressure, you already know how much CO2 is in solution. If you make a "bleed-off gauge" or whatever you might call it (NB part #K088), you can measure the pressure, but that is not really ever needed because the proper pressure is what your regulator should be set at for serving. If you are just setting your regulator to some arbitrary number and letting the beer sit until it "seems right" you deserve whatever happens.
After doing this for a long time now, I have a decent grip on rapidly force carbonating my brew. Before I do any racking, I chill the vessel/fermenter for a few days whether it be primary or secondary, to make sure the yeast drops out as much as possible, then I'm racking cold clear beer into the keg to start with and don't need to chill the beer much if any before carbonation. If you can't chill your fermenter, no worries, just get the beer in the keg cold before carbonating. Once I get the beer into the keg, I start with setting the regulator to about 50psi for the first shaking segment, connect the CO2 line to the GAS (IN) port, and then lay the keg on its side and roll back and forth for about 15 seconds listening to the bubbles. I then turn down the gas pressue while rocking the keg and listening to the bubbles, and stop lowering the pressure when the gas bubbles stop. I don't go below the point where beer flows into the line. I continue rocking the keg and the bubbles will start again as the gas present goes into solution and the overall pressure drops so the gas flows again. Once the bubbles become fast again I continue rocking while turning the gas down again, probably 5psi at a time. I do this again and again until I get to about 20psi on the regulator. At this point I'm really close to the final pressure I want so I drop the pressure to a few pounds above my target and shake until the bubbles slow again and I stop. This only takes a few minutes. This usually gets me to a place where the beer is carbonated enough to be served, but still usually needs some time at the proper final pressure to be perfect. Stopping a bit early prevents me from over-carbonating. If you get really good at this you can just about get it 100% perfect this way and very quickly and be perfect, but people tend to overcarb so I suggest caution.
It is still better than setting at a higher pressure and leaving it for hours or days and not knowing where your carbonation level is. This method is a controlled way to get close to your target carbonation, and you can then get the last few PSI done by leaving it overnight and be perfect, and accurate very quickly.
This method is nothing new, and yields very accurate and trouble-free rapid carbonation. I've never over-carbed doing this because the high-pressure segments are quite short, and you have an audible reference to let you know when the pressure is reaching equilibrium at the 20psi segment. I'll be glad to show anyone how to perform this method if you are in the
We also assume at this point that you have a balanced serving system. If you do not have a balanced serving system, and are doing strange things to serve your beer, that is a whole diffferent story.You should be able to set your regulator at the same pressure as you carbed your beer for, and serve perfectly. If not, fix it. Skip the tricks and do it right, and thank us later.
If you ever meet someone who tells you to just set the regulator at some higher pressure and walk away for a few days until it seems right, kick him in the head for the rest of us because that causes more problems and more redundant postings than anything else I've ever seen.
http://www.homebrew.com/articles/article12018101.shtml
http://sdcollins.home.mindspring.com/ForceCarbonation.html
