January 8, 2019

What is Nitro Coffee?

Coffee can be had a million different ways – black, with creamer, from the press, drip, filter, or machine, decaffeinated or imbued with extra sugar and flavorings – but more recently, coffee is being served with nitrogen gas straight out of a tap. That might sound strange to you, but it will all make sense in a second. Riding in on the back of the cold brew coffee trend, nitro coffee (or nitro cold brew coffee) is a relatively new form of coffee first introduced to the world just a few years ago, sometime around 2011-2013. While the exact origins are unclear and partially disputed, the drink has grown past its origins in the US and become an international phenomenon, with coffee shops offering nitro coffee throughout Europe, Asia, and other regions in the world.

Nitro coffee is, put simply, cold brew coffee infused with nitrogen gas. Much like soft drinks – which are sticky and sweet concoctions mixed with carbon dioxide – adding gas completely changes the drink. Nitro coffee is foamy, creamy, and almost sweet, despite not containing any creamer or sugar. Made simply with cold-brewed black coffee and nitrogen gas, nitro coffee is made with the same principle as the world-famous Guinness beer, which gets its creamy consistency due to the same trick of chemistry.

The History

To fully understand how nitro coffee came to be, we have to take a step back and go into the history of the cold brew coffee. Cold brew coffee was a growing trend and a precursor to the invention of nitro coffee, but its true roots go back much farther than most people might realize. While the coffee plant was first harvested and used for its medicinal benefits (the potent effects of caffeine) several centuries ago in East Africa and the Middle East, the spread of coffee to Europe through smuggling and cross-cultural trade paved the way for an explosion of coffee-based recipes, drinks, and desserts – some of which came to be out of a desire for experimentation, and others out of the necessity for coffee in newer, more long-lasting forms.

Cold brew coffee, for the uninitiated, is coffee brewed with cold or room-temperature water. Instead of relying on hot water to steep coffee grounds for their rich oils and flavor, cold brew coffee requires a much longer brewing process, yet creates a completely different drink. As far as we know, it was the sea-faring Dutch who first started the practice, either back home or over the tides of the oceans. Pre-brewed coffee grew stale quickly and wasn’t enjoyable cold while brewing batches of coffee on-board with roasted beans was too much of a hassle and would presumably require much more space. By pre-brewing the ground coffee into cold brew coffee concentrate, the Dutch would have an easily-stored liquid form of caffeine available at all times, hot or cold.  

Thus, someone came up with the idea of preparing coffee concentrate, which would keep for a long time and could simply be mixed with hot water to prepare coffee. The concentrate was created cheaply through clean water and ground coffee – instead of pouring hot water onto the grounds, however, the water would be slowly fed into the grounds, and through a filter, resulting in a very slow extraction process as the water would, drip for drip, make its way through the grounds and into a separate container.

The Dutch were not the only ones to prepare cold brewed coffee concentrate, especially as a way to cut down on space needed to keep coffee. The practice was spread to Japan, England, and the Americas, especially among those in the military or navy.

Cold coffee was enjoyed many different ways ever since. It became a cultural mainstay in France after French soldiers enjoyed a form of iced coffee involving sweetened coffee syrup, water, and rum, and cold brew coffee (especially served in a can) became incredibly popular in Japan in the 1960s, by way of the Ueshima Coffee Company.

In the same vein, Japan popularized an excruciatingly slow form of brewing known usually as the Kyoto-style drip – coffee made in a tall still that very slowly drip-feeds a reservoir of water into a paper filter filled with ground coffee, saturating the grounds before very slowly extracting into a cup or glass below. The water in the reservoir is often cooled and never warm or hot, and the process can take anywhere from six to 24 hours to complete. This slow-drip coffee is typically very expensive, as the still itself is quite pricey and incredibly tedious to take apart, thoroughly clean, and put back together.

Fast forward over 50 years, and cold coffee has become a staple simply for the fact that it’s easy to market, sell, and drink. Canned coffee, coffee concentrates, and cold coffee drinks produced with coffee made through the cold-brew process are numerous, although some brands utilize instant coffee rather than cold brew coffee or coffee concentrate for their drinks. Amidst the hunger for new and exciting ways to drink the same brew we usually enjoy; nitro coffee was born.

It was Nate Armbrust, working out of Portland, Oregon’s Stumptown Coffee Roasters, who discovered and began the amazing trend of nitro coffee. First experimenting with carbonated coffee, he realized that while it works well with juices and sweet concentrates, carbonation destroys the unique flavors in brewed coffee and simply adds to the preexisting acidity, which is typically an undesirable trait associated with bitterness and over-steeping. After coffee soda was a bust, he took a page from his days home-brewing beer and gave nitrogen gas a try, inspired by the popular Irish stout, Guinness.

After showing initial promise, he refined his idea until he found the right gas-to-coffee mixture and pressure level to produce quality coffee straight from the tap. Then, Stumptown Coffee began serving nitro coffee through kegs produced as per Nate’s original formula. This was back in 2013, and Stumptown wasn’t the only café experimenting with nitrogen in coffee.

Mike McKim, owner of Cuvee Coffee, came up with the same idea after seeing cold coffee served on tap, becoming obsessed with the idea of serving coffee like beer. Both McKim and Armbrust saw to it that nitro coffee spread throughout the country, by figuring out ways to not only serve their creations to local customers, but package them in cans and ship them throughout the country (and soon, the world).

In the five years since then, nitro coffee has been popularized not only by small coffee shops throughout America, Europe, and Asia, but by big-name coffee chains like Starbucks and Dunkin Donuts. Today, there are dozens of companies producing canned nitro coffee, and even more cafes serving it to customers worldwide. But how is it made, and how is it different?

The Process

Nitro coffee is cold brew coffee infused with nitrogen. It isn’t regular brewed coffee left out to get cold, and it isn’t water mixed with coffee concentrate. It’s coffee brewed with cooled or room-temperature water, kept in storage kegs with nitrogen gas, and poured through a tap at high pressure. The faucet of each tap has a restrictor disc, which is basically a metal filter with lots of tiny holes. This is what causes the coffee to come out of the tap in its rich and creamy form.

The science behind this is simple. While sodas like Coca Cola rely on the nature of carbon dioxide to create tons of large bubbles in their drinks and create an acidic bite with each gulp, nitrogen gas creates much smaller bubbles. When pressed through a restrictor disc, this sends a blend of iced coffee and gas into a glass, where the bubbles of the gas quickly separate from the liquid coffee and rise to the top, creating a creamy, foamy head, similar to what you’d see when pouring a glass of Guinness. Meanwhile, the coffee itself is also creamier and smoother than regular iced coffee, owing to the levels of gas in the drink.

Nitrogen does nothing to change the taste of coffee. But it does change the mouthfeel, which alters the tongue and mouth’s perception of certain tastes. By mixing nitrogen into black cold coffee, it gives it a sweeter taste, and removes a certain level of acidity.

Making Nitro Coffee at Home

Making nitro coffee when you’re a café owner with access to a tap, nitrogen supply, industrial kegs and cold-brew coffee is quite simple, as long as you’re willing to experiment with coffee-to-gas ratios and storage methods. But when trying to replicate nitro coffee at home, you’ll want to get creative.

While there are nitro machines out there for purchase with big bucks, a relatively cheap way to create your own nitro coffee is by feeding cold brew coffee into a cream whipper and loading the whipper with a cartridge of N2O (nitrous oxide, a gaseous mixture of oxygen and nitrogen). Shake wait for a few minutes, then pour into a glass through the nozzle.

The hardest part here will be making the cold-brew coffee itself. You’ll want to prepare it beforehand, steeping coffee for at least a full day before mixing it with the gases.