After beer has been brewed; that is, sugar has been extracted from grain, the resulting sugary liquid (wort) has been boiled, and then yeast has been added and fermentation has taken place, the result is essentialy beer. One ingredient is missing, however; carbonation.
This is a favorite element of beer, not only making it quite drinkable (speaking here of the light and refreshing feel in one’s mouth) but enhancing the aroma and flavor. But how is beer carbonated? Like many things in life, consumers often take this for granted. A few curious beer drinkers have asked me–being a home brewer–how I carbonate my beer. Most are clueless. One individual guessed that I added carbonated water to my fermented wort. This isn’t the case. Typically, there are two methods for carbonation: forced and natural.
Forced carbonation inserts the CO2 into the beer. The beer is place into a sealed (or soon to be sealed) container and carbonation is rapidly added. Under high pressure, the CO2 is absorbed into the beer. This is actually the preferred method for most breweries, as the turn around time for a finished beer is quicker, and the bottle contains little to no sediment, as the beer has been pasteurized and yeast removed from the liquid.
Natural carbonation allows yeast to remain in the beer. Sugar is then added to the beer in its container and then sealed. Fermentation kicks off again as the yeast eats the new sugar addition. When yeast ferments, it releases CO2 which is then absorbed into the liquid? So which is better? How are they different?
For the greater part of my tenure as a home brewer I relied on natural carbonation, as I didn’t have a kegging system to force carbonate my beer; I would rather spend my money on beer ingredients than the costly upgrade to kegging equipment. This past Christmas, my dad surprised my with kegging equipment and the opportunity for forced carbonation. As an experiment, I brewed two nearly identical batched of beer and carbonated them differently for comparison.
There is a marked difference.
The force carbonated beer looks better. The bottom of the bottle boasts no sediment, and the beer pours crystal clear. It looks like it was pulled right out of a sixpack from your typical craft brewery. It pours with a decent head and bubbles cling to the inside of the glass. Lacing is minimal.
The beer carbonated ye old naturale method has a thin layer of yeast on the bottom. The head is thicker and more billowy with more peaks and valleys, and it has longer retention with more lacing. There are fewer bubbles sticking to the glass (both dishwasher cleaned) and the bubbles are tinier. In the mouth, the beer feels smoother than the force carbonated beer, and more effervescent; perhaps more champagne like, though both feel as they have the same level of carbonation. The beer that was carbonated induces more belching.
Flavor? Yes, there is a difference.
The beer that was carbonated naturally has a slight yeast bite. It is a bit more bready; an attribute many homebrewers avoid. I myself enjoy it. The naturally fruity (no fruit was used in the making of this beer) qualities of the Belgian yeast strain are much more prominent and there is an overall level of complexity not attained to by the beer that was carbonated by force.
Admittedly, I am just scratching the surface of this complex topic, but so far, I prefer natural carbonation (sometimes referred to as refermentation). I intend on repeating this experiment repeatedly and am aware that there are more complex and specialized pieces of equipment for better forced carbonation, and also realize that my beer that was force carbonated had not been rid of residual yeast.
Home brewers and pro brewers, what are your thoughts? Non brewers who just love beer, what are your thoughts?