Nitro Beers, Explained :
Beers naturally carbonate in fermentation as the yeast turns sugar to alcohol it releases carbon dioxide creating carbonation, or those bubbles like a soda. They can be further carbonated in bottling depending on brewers preferences.
When a beer is “on nitro”, usually delineated on a menu in parenthesis, it means that nitrogen is added to the beer, in addition to the CO2.
“Most nitro beers are mildly carbonated. But the addition of nitrogen—an insoluble gas that forms smaller, more profuse bubbles than carbon dioxide—gives beer a smoother texture.”
There are a few reasons beers are put on nitro, but the ultimate end result is the smooth, silky, almost milky texture given to the beer in the process. And the reason it takes on this new mouth feel (and aroma/flavor) is the type of bubbles.
Historically, Guinness is the brewery that developed and made popular the process. Left Hand Milk Stout is another common “nitro” beer. In the past, and still today, most nitro beers are heavier ones. Your porters and stouts. Nitrogen tends to remove or dramatically lessen the floral/citrus/hoppy flavors of IPAs or other hopped/citrus beers. The one thing it can do is mellow out an intense, leggy stout. If the booze is a little strong or prickly on the nose and taste buds, nitro rounds it out and allows it to be creamier and less effusive.
Say No to Nitro Beer :
According to the article “say no to nitro beer” the original use of nitro was to boost the carbonation of cask beers that couldn’t be pressurized enough to stay effervescent. Though obviously, the trend has stuck around because people enjoy the smoothness it lends to an otherwise intense or “prickly” beer.
Most beers served on draft as “nitro” are a mix of 70% nitrogen and 30% carbon dioxide, called “beer gas” which mimics the natural 80%/20% nitrogen/oxygen cask ales had naturally. An interesting characteristic of nitrogen is that it doesn’t stay in a solution for as long as CO2, so drink it fast, or it will go flat pretty quickly (30ish minutes).
Good Beer Gas: Nitro Beers Explained :
The addition of nitro creates a reverse cascading effect that is certainly visually satisfying. It also creates a thick, fluffy, long-lasting head, creating that milk mustache.
While this article didn’t bring any new information from the earlier ones I read, it was amusing that I found this, which is a glowing review and endorsement of nitro in beer that followed one all about why it sucks. It made me smile.
Guinness Cans Hide a Weird Plastic Ball — Here’s How It Works and Why it Makes Your Beer Extra Delicious :
“During the canning process, brewers add pressurized nitrogen to the brew, which trickles into the hole along with a little bit of beer. The entire can is then pressurized.
When you open the can, the pressure inside drops to equalize with the pressure in the room. But the pressure inside the widget is still much higher than the pressure in the beer around it, since the gas can escape only through a tiny hole. That makes the nitrogen inside the widget squirt into the beer like a jet. This blast creates a burst of tiny nitrogen bubbles that rise to the top of beer, giving it a thick, creamy head like the one you’d get from a tap.
They are also mostly only available on tap, as that’s an easier way to administer the nitrogen. But more and more, beers are popping up in cans on nitro. Apparently this is a bit secretive. Guinness has been doing it for a while with their plastic widget that allows for the nitro when exposed to oxygen.”
“Guinness brewers first patented the idea of the widget in 1969, but it wasn’t until 20 years later that they released their first-generation widget.”
Additional Resources used in this episode:
Craft Beer Tasting Sheet