When it comes to kegs, the choice of whether to use nitrogen or CO2 depends on the type of beverage being served. As a sommelier and brewer, I have had the opportunity to work with both gases and understand their different effects on beverages.
CO2, or carbon dioxide, is commonly used for beverages that are meant to have bubbles. This includes carbonated drinks like soda, sparkling water, and beer. CO2 is highly soluble in water, which allows it to create those delightful bubbles that tickle our taste buds. When CO2 is injected into a keg, it dissolves into the liquid, resulting in the formation of small bubbles. These bubbles add effervescence and enhance the drinking experience.
On the other hand, nitrogen is used for beverages that are not intended to be carbonated. Nitrogen bubbles are larger and creamier than CO2 bubbles, giving the beverage a smooth and velvety texture. This makes nitrogen a popular choice for beers like stouts, porters, and nitro cold brew coffee. When nitrogen is introduced into a keg, it displaces the oxygen and creates a pressurized environment, allowing the beverage to flow smoothly without excessive carbonation.
One way to remember which gas to use is to consider the intended level of carbonation. If the beverage is supposed to be carbonated with small bubbles, CO2 is the way to go. If the beverage is meant to be smooth and creamy without carbonation, nitrogen is the preferred choice.
Personally, I have found that using nitrogen in kegs for certain beers can significantly enhance the drinking experience. Nitro stouts, for example, have a distinct velvety mouthfeel that is achieved by using a mix of nitrogen and CO2. This combination creates a perfect balance between carbonation and creaminess, resulting in a rich and indulgent beer.
It is worth mentioning that there are also blends of CO2 and nitrogen, known as beer gas, which can be used for specific beer styles that require a moderate level of carbonation and a creamy texture. This allows brewers to customize the gas mixture according to their desired outcome.
The choice between using nitrogen or CO2 in kegs depends on the desired outcome of the beverage. If bubbles are desired, CO2 is the gas of choice, while nitrogen is used for beverages that should be smooth and creamy without excessive carbonation. However, there are also instances where a blend of both gases, known as beer gas, can be used to achieve a specific texture and carbonation level.