By Ale Clayson

Many homebrewers approach their beer with a fierce sense of pride and the idea of force (artificially) carbonating their beer will send shivers down their spine. "Nothing artificial in my beer, dammit!" Let's look at this from a different angle. When you bottle you add a measured dose of sugar to your beer to allow the residual yeast to referment in the bottle and create the carbonation in a bottle-conditioned beer.

This method is tried and true but completely ignores the following variants:

1) Yeast viability. After fermenting your beer, especially if it's a higher gravity beer of 1.060 or more your yeast may be tired out and might not be up to the task.

2) Sediment. Although it's good for you, it's not pretty. This is probably the single biggest turn-off to the average non-educated beer drinker.

3) Balance. Many homebrewers shudder at the idea of deviating from the Reinheitsgebot (German purity law of 1516 - a very noble stance to take) and would rather prime with DME instead of dextrose or force carbonation. Here's the catch: breweries that naturally carbonate their beer either use refined sugar which is considered 100% fermentable (common in England and Belgium) or they Kraeusen (common in Germany) with fresh wort and yeast. This wort is from batches of the same beer as what's being carbonated, and hopped the same way. Malt based sugars are about 70% fermentable. That remaining 30% are going to alter the character of the final product.

Force carbonating will allow you to hit your desired level every time, without exception, and I'll let you in on a secret - there are a lot of breweries in Germany that force carbonate using reclaimed CO2 from their primary ferments, thereby adhering to the Reinheitsgebot.

There are two methods of force carbonating your beer in a 5-gallon soda (Cornelius) keg. The patient method (recommended) and the impatient method (relax-don't worry-you know the drill). The patient method will always give you the best results. It's based strictly on numbers so you can do it over and over and achieve the same results every time.

The amount of CO2 that will dissolve into your beer is dependent on two factors - temperature and pressure (refer to the PDF chart). Generally ales tend to be carbonated at the lower end, 1.9 to around 2.3; most German style lagers at around 2.4 to 2.7; and American lagers, Japanese lagers, and wheat beers at around 2.7 to 3.0. The amount of CO2 dissolved in beer is most often referred to in terms of volumes. Volumes of CO2 are defined as the volume the CO2 gas would occupy if it were removed from the beer at atmospheric pressure and 0° C, compared to the original volume of beer. Most beers in the United States contain roughly 2.5 volumes of carbon dioxide, or about 5 grams per liter. This means that if all the carbon dioxide in one liter of beer were expanded at 0° C and at one atmosphere of pressure, its volume would be 2.5 liters.