Nitro cold brew coffee is simply coffee that has been cooled to at least 40C which is equivalent to 400F before being infused with nitrogen (N2) gas. Various methods can be used for brewing the coffee before it is infused with N2. The most popular method is cold brewing. Infusing the nitrogen into the coffee is done with either of two methods. One is through pressurization of the coffee in a pressure vessel such as a keg. Second, through the use of a device known as a Nitrogenator, which works in a similar manner to how a soda-pop machine carbonates the beverage with Carbon Dioxide.
The coffee has to be held under a pressure of at least 3 bars (40 psi) to maintain good nitrogen saturation of the coffee. To accomplish this, one has to store the nitro coffee in a keg. When fully nitrogenated and cooled properly, nitro coffee has beautiful presentation when served in a clear glass. As the coffee is dispensed out from under pressure from the tap faucet, the micro-fine nitrogen bubbles will rise gently from the solution displacing the coffee and forcing it to settle downwards causing a visual event called the falling. The nitrogen bubbles then accumulate on top of the beverage, creating what is referred to as the head. The accumulation of the nitrogen bubbles adheres to the natural sugars and oils contained in the coffee itself and so the head exhibits a creamy & sweet taste. The appearance is similar to that of a crema on the top of a shot of espresso. When enjoyed, the coffee provides a refreshment similar to a dark beer but with a definite coffee flavor. The beverage has a smooth, somewhat viscous mouthfeel and many people enjoy it black without adding cream or sugar. Just like other coffee drinks, it will also provide you with a natural lift from the caffeine.