Force Carbonating Homebrew

2011-10-17 Update

In the four years since I originally published this post, my methods have gotten a tad more *ahem* sophisticated. There's actually a proper way to carbonate your brew which will result in the desired level of CO2 for the particular style you've brewed.

First, you'll want to find the desired level of CO2 for the style you've just painstakingly brewed. Here are some general guidelines and a helpful calculator. After you've racked into your sanitized and pressure-tested keg, hook up the CO2 disconnect and dial the pressure on your regulator to the one indicated on the calculator. Leave the keg on the CO2 for 24-48 hours, gently rocking it back and forth occasionally if you're inclined to speed the process up a bit. Bleed the pressure in your keg and dial it back down to your dispensing pressure.

The method I recommended below can still work in a pinch, but there's a good chance you'll decrease the head retention of your beer by using it.

*(In case you were wondering why temperature matters, CO2 and all gasses are more soluble in liquids when they're at a lower temperature. To get really nerdy: the molecules in a liquid move around faster at higher temperature. This motion is the result of increased kinetic energy and is sufficient to break the weak bonds holding that gas in solution.)

Original Post: 
So as I previously mentioned, one of the things that ultimately pushed me over the edge into procuring a kegerator was the fact that I had a batch of double IPA which failed to carbonate itself when bottled. (I had so much time invested in this brew that I couldn't bear to let it go to waste.)

Naturally, the first thing that I did once I'd completed the kegerator conversion was to force-carbonate the double IPA. And seeing as I'd already waited a really long time to try this beer, I opted for the "High Pressure and Brute Force" methodology of carbonation. In other words:

• chill the beer
• apply about 20-30 psi to the cornelius keg with only the gas disconnect attached
• shake the crap out of the keg
• put back in the fridge
• repeat a few times

Unfortunately, I didn't take precise notes as to how long the keg was pressurized at what specific psi. But after a few days at high pressure with a few shakes each day, I bled some CO2 out and backed the pressure down to about 8 psi. The end result is just a bit more carbonated than I would've intended, but still very nice.

Next time I'll probably opt for natural carbonation in the cornelius keg (a la bottle conditioning) or for the "Low and Slow" method of applying dispensing pressure over about a week or two.