CO2 Mixed Gas

There are many benefits to using mixed gas, such as a combination between CO2 and N2, when choosing the gas to use on your draft beer. Below is a list of the different negatives and benefits of using different types and mixes of gas.

Atmospheric Air

N2, CO2, O2, Pollution, Pollen, Bacteria and Wild Yeast – air is bad for beer as it causes oxidation, which in turn ruins the flavour of beer. Air makes beer taste like wet cardboard. Even though air contains some parts of the good gases for beer (Carbon dioxide and Nitrogen), the presence of oxygen makes it unusable in a draft beer pressure system. That doesn’t mean that it is not used. Some bars still use compressed air to pressurize their draft systems. Air is also used to pressurize kegs via a hand pump at parties. In an application like this the air is acceptable because the beer will be finished within a day yet it is definitely not recommended on any permanent basis. It is also impossible to tell the actual content of the gases in the air so cannot be used by any licenced premises.

Carbon Dioxide

This is a naturally occurring gas that is highly soluble (dissolves easily) in beer. In fact, CO2 is a natural component of beer as a major by-product of the fermentation process, another being alcohol. CO2 gives beer its characteristic head and provides a slight bittering in taste (a desirable quality in beer). CO2 also provides effervescence that helps “lift” the beer’s aromas into the drinker’s nose and palate. This is often a good alternative to mixed gas.

Nitrogen

Though it is another naturally occurring gas, N2 is insoluble meaning that it is hard to dissolve in beer. Nitrogen has two similar purposes for use with draft beer: (1) to allow high pressure dispensing through heavily restrictive apparatus (causing notable frothing) as in Guinness and similar products; (2) to allow high enough gas pressures to overcome the resistance inherent in long beer lines. In both of these cases the goal is to push the beer at high pressure but not alter the carbonation of the beer as it sits in a keg. This is accomplished by using insoluble Nitrogen mixed with the soluble CO2, and is the most common variety of mixed gas.

Beer Gas, Draft Gas

This pre-blended gas is a blend of Carbon Dioxide (25%) and Nitrogen (75%) made specifically for use with Guinness Stout and other similar beers. This mixed gas is used to allow the high pressures needed to force the beer through a restrictor plate in a specialty faucet. This is to create the frothy pours characteristic of this style. In this type of application, the use of CO2 alone would quickly over carbonate the beer and pouring would be impossible. This mix is also very commonly, but incorrectly, used to pressurize the long line draft systems common in many restaurants and bars. This is not the proper ratio of mixed gases to serve standard ales and lagers. Beer Gas is however, the only pre-blended gas commonly available – creating confusion over its proper usage.

For more on getting mixed gas on your property visit the CO2 Gas Company.

Related articles

• Carbon Dioxide: The ‘Gas Of Life’ (1389blog.com)
• Designing a Draft Beer System for Your Home (realsolutions4realestate.wordpress.com)
• Fracked Shale Could Sequester Carbon Dioxide (science.slashdot.org)