Beer 101

Nitro beers, or beer that has been prepared with nitrogen instead of carbon dioxide as the engine that drives bubbles and the foamy head, is a relatively modern concept. The key idea came out of Guinness’s attempts to revolutionize their beer in the middle of the 20th century. It’s controversial, because while nitro changes the head and foam to an interesting new feeling that can’t be replicated with carbon dioxide alone, it also has the reputation of deadening beer flavor. In this post, we will talk about why craft breweries are revisiting nitro today.

Nitrogen is a gas that the bartender injects into the beer and mixes in at the time when the beer comes out of the tap. It takes special tap equipment to pour a nitro beer, but it is increasingly common for craft beer bars to offer at least one beer with nitro.

The primary effect of nitro is the way it changes the head and foam of the beer. To be specific, the head is composed of very small bubbles that taste thick and creamy. The most obvious and common example of a beer with a nitro pour is Guinness. The sweet and creamy thick head on a Guinness is characteristic of the presence of nitro.

Generally, the way nitro works is that the tap has a special tank for nitrogen gas attached to it. When the bartender opens the tap to pour, some nitrogen mixes in with the beer because a valve opens up, letting nitrogen flow from the tank to the tap. The effect can be dramatic if you compare a beer without nitro to the same peer poured with nitro.

The controversial element of nitrogen is that it has a tendency to mask the underlying flavor of the beer. Compared to other stouts, many would say that Guinness is not very flavorful. The tradeoff is in adding the excellent head, but removing some of the subtle, nuanced flavors.

However, more and more craft breweries are experimenting with nitrogen. While it originally was a draft trick to help Guinness pour more consistent beer, there are now breweries that design and bottle beers as nitros from the beginning. This is most common with stouts and porters, who benefit from the sweet creaminess of a nitro head and don’t have the fruity undertones of hoppier beers. Sam Adams recently launched the Nitro Project, which is aimed at bringing high-quality nitro beer to consumers in cans. The Nitro Project beers include Nitro Coffee stout, Nitro IPA, and Nitro White Ale.

Sam Adams Nitro Beers Project

A diagram explaining how the nitro cans work in the Sam Adams Nitro Project. Image via Samuel Adams Nitor Project.

Overall, nitro in the past few years has become a growing part of the craft beer portfolio. It has demonstrated that it is not just a gimmick, but if you build a beer around nitro, you can create great things. That’s why so many bars have nitro taps and why more breweries are using nitro: it’s a new spin on old flavors and its use reflects the dynamism of the craft movement itself.