Feeling Gassy? CO2 vs Nitrogen in Beer

Posted on: March 30th 2015

Let’s talk gas. Beer has it…and it shows up visually in the form of bubbles.

When you order a pint at your local watering hole, it will most likely be served using CO2 or carbon dioxide. During fermentation, yeast in the tank/vessel eat sugars from the liquid (called wort or sweet barley tea) and naturally there are two bi-products from this process…alcohol and CO2. Before the beer goes from the fermentation vessels to a brite tank (where the beer settles before bottling), or directly to racking for kegging, it is often force carbonated to give the beer fizz, flavors and aromas.

CO2 is a clear colorless gas that gives oomph to your liquids. Based upon temperature and pressure (psi), you can have a beer that is over carbonated, under carbonated or just right (sounds like Goldilocks and the Three Bears). We recommend serving your beer cool because if it’s too cold, it stifles the CO2 and if it’s too warm, you may get a gusher!

Nitrogenated beer, on the other hand, infuses nitrogen gas into beer and is largely insoluble (hard to dissolve) in the liquid. This gas gives beer a creamy and smooth mouth feel (tiny bubbles – now that song is in our heads). Nitro beers also tend to have less perceived bitterness because CO2 is acidic which adds to bitterness perception. There are mixed opinions on this so you must try a Nitro beer vs a Carbonated beer side by side and see for yourself (you can often get the CO2 version and Nitro version together at our pubs and tasting room).

Nitro beers have become quite popular in the craft beer industry. It seems as though in this day and age, consumers are excited for that new experimental beer; something that is different from the norm (not the Norm from Cheers, where everybody knows your name). Although Nitro beers like Guinness have been around for decades, other breweries are getting into the game with more than just stout. And many breweries keg their Nitro beers but only a couple have actually mastered Nitro in the bottle. Guinness has a widget inside the bottle or can so when you pop the top, the gas is released. On the other side of the spectrum, Left Hand Brewing Company has a particular pour from the bottle of their Milk Stout that creates that creamy Nitro head.

Here at Deschutes Brewery, we love to experiment and have been making Obsidian Stout on Nitro for years. Be sure to try it with vanilla bean ice cream for the tastiest Nitro Stout Float, ever! Recently, we’ve created our own Nitro line-up! In addition to our year round Nitro Obsidian Stout, you can also find seasonal Nitro beers like Red Chair NWPA, Jubelale, and the two new ones in 2016 are Cream Ale and Black Butte Porter.

Basically we add Nitrogen instead of CO2, to the beer after it gets clarified. That addition happens through porous stones in the lines as the liquid passes by. It must then go into a “rated” vessel. Rated means they have been made, in part, to specifically hold a higher pressure. In this case these tanks are rated to ≥25 psi rather than 15 psi which is typical of most tanks in most cellars. This higher pressure aids in holding the Nitrogen in solution. Once the tank is full, we measure the amount of CO2, Nitrogen (usually 30/70 mixture) and dissolved oxygen to make sure each one is within our control specifications. We also pour sample pints through a special tap rig to time the “Fallout” or “Bubble Cascading Effect”. We’re looking for 90 seconds from pint full until you have that perfect thick head, crisply differentiated from the body of the beer. Once everything on our end is right, the beer gets kegged and sold to our distributor, then to bars, and then poured from a restrictive faucet tap into your glass. Voilà!

Whether you are a fan of CO2, Nitro or both, there are a ton of beers out there for you to try so get to it! If you haven’t had the chance to try our Nitro line-up, we highly recommend them and be sure to compare and contrast the flavors and aromas to the original CO2 versions. We think you’ll enjoy both for different reasons. Cheers and here’s to FEELING GASSY!