Craft beer, like any other market, is full of fads and offerings to differentiate one beer from another. Some fads come and go with a whisper. Others stay around and continue to gain popularity. One such fad is the addition of nitro, or nitrogen, in beer.
While this may not technically be a fad in the truest sense of the term, after all Guinness has offered its popular stout on nitro for decades. However, the addition of nitro to a wide variety of beer styles, is building with nearly every beer style over the past few years.
What exactly is nitro and what is it doing to our beer? Does it make the beer better?
First, lets get a little scientific to better understand the difference. Standard beers offer the refreshingly prickly CO2 bubbles common in beer. CO2 is a natural bi-product in the beer-making process. As beer ferments yeast consume sugars and produces two bi-products one being alcohol (yay!) and the other, CO2. Beer is often forced carbonated to give it that wonderful bubbly mouthfeel.
The amount of CO2 in your beer will vary upon style, but the perfect balance is always sought to create the best beer possible. CO2 should be controlled in beer once you grab a six pack. Keep the beer stored cool, but not too cold otherwise it stifles the CO2 and if it’s stored too warm then you may have a mess on your hands when you pry that cap off.
So what does nitro do to the beer? The simple answer is that it reduces the amount of CO2 in the beer and creates much finer bubbles in the beer. These smaller bubbles dramatically change the mouthfeel of the beer and impart a very full and smooth texture to any beer.
Typically most beers that are put through this process have a ratio of 70 percent nitrogen and 30 percent CO2. This ratio helps the beer still feel carbonated, but adds a very different experience.
As the popularity of nitrogen in beers has grown, brewers have evolved in ways of adding nitro to beer for bottling and canning. For many years Guinness canned its popular stout on nitro through the use of a widget that would be left to rattle around in the can after completion. However, brewers discovered new ways to can or bottle with a loose widget.
If you tried a nitro beer on tap, that is done through a different process. Bars will have a system where nitrogen mixes with the beer as it is poured.
Left Hand Brewing made news when it released bottles of their extremely popular Milk Stout on nitro. What was newsworthy was the beer was bottled with no widget or gadget inside and instead was just a “normal” beer in a bottle that poured just like a nitro beer.
Speaking of pouring, this is another big difference between nitro beers and standard beers. If you pour a standard beer from a bottle aggressively, that is very fast and turning the bottle straight upside down in a glass; you will have a beer that quickly overflows leaving half of the contents on your counter and floor. However, with a nitro beer you can be extremely aggressive with your pour and the beer will not quickly rise and overflow your glass.
The difference between these pours comes from the gas escaping from the beer. CO2 has larger bubbles compared to the nitrogen beer’s smaller bubbles. These bubbles are the gas and as they pour they are stirred up and are looking to move around. The nitro beers are smaller and not as aggressive which leads to very smooth pours that are quite fun to watch.
Now the big question, does it make the beer better? Well that is not an easy answer. It is partly based on personal taste, but also based upon the beer style. More delicate beers, such as many Belgian styles, would not really benefit from being put on nitro as the process would muffle many of the subtle nuances from the flavors. However, thick stouts and porters gain huge benefits from the nitro process that both enhance the malt character and bring forward bold flavors. Whatever your preference, nitro beers are here to stay.
Derek Warren is a beer fanatic, avid homebrewer and beer historian. Derek can be heard weekly on the Beer Geeks Radio Hour at noon on Sundays on WILK 103.1 FM with past episodes available on iTunes.