Nitro cold brew coffee, commonly referred to as "NCB," is cold brew coffee charged with nitrogen to give it a rich, creamy head, similar to nitro draft beer like Guinness. Though many beers are infused with carbon dioxide, darker stouts are occasionally infused with nitrogen, resulting in a smooth finish from the beer. This is a direct effect of nitrogen bubbles being smaller in size than those of carbon dioxide, resulting in a beverage with a thicker mouthfeel.
We brew coffee in an environment free from contact with any harmful chemicals or compounds and keeps it safe for human consumption. The “nitro” that we use and refer to in our name, is pure food grade nitrogen gas. Nitrogen is an inert gas meaning that it is not chemically reactive. N2gas is common to humans and is safe to inhale when mixed with oxygen. We know this because 78% of the air that we breath is Nitrogen gas. To obtain this gas, a separation process is employed. The separation process eliminates trace gases, carbon dioxide, and oxygen, leaving at least 99.8% pure Nitrogen. The food grade nitrogen used throughout the brewing and manufacturing process of our products is pure and acquired from a certified source. It is used as a process agent, a visual enhancer, a preservative for the finished product and finally as a propellant to push the product from the kegs to the tap faucet at the dispenser. The “nitro” in the nitro cold brew coffee has nothing that can affect your health negatively. Rather, as has been outlined previously, what it adds to the coffee is good.
It is commonly thought that Nitro coffee made from coffee brewed with the cold brew process has lower acidity and higher in caffeine when compared to hot brewed coffee. Coffee brewed in hot water increases the speed of the extraction of the dissolved solids, some of which are flavor producing acids, caffeine, and numerous other alkaloids. The cold brew process, which is often used for brewing nitro coffee, decreases the rate of extraction so it requires more time for the process to take place. The time is typically 12 – 24 hours.
Is it true then, that cold brewed coffee has less acid? To understand this, let’s consider what the term “acidity” means in coffee. The volatile acids that contribute to flavor in coffee are referred to as perceived acidity. These are less obvious than, the “total acidity” of the brew that one could measure with a pH meter. Perceived acidity is the subtle sensation you experience from the flavor producing acids in the coffee as they interact with your taste buds. They are immeasurable with a pH meter and they are highly affected by oxygen.
So what is really going on with a cold brew that causes us to perceive it as less acid is directly due to the oxidation that takes place during the cold brew extraction process? During this extended brew time oxidation destroys many of the taste producing volatile acids and renders the final brew very flat and single dimensional tasting. It is not due to the temperature of the water in which it is extracted, but rather, it is due to oxidation of the flavor producing acids. Much in the same way that fine red wine goes flat and tasteless when it is exposed to air (allowed to breathe) for too long, leaving coffee in an open-air container to let it extract in cold water causes irreparable damage to the flavor due to uncontrolled oxidation. While it still tastes like coffee, it has lost much of the unique flavor producing components that existed in the form of volatile acids. To go a step further, variations in acidity between different brews are more often caused by variations in water pH. This makes sense as coffee is around 98% water. Brew water pH is also directly correlated to the filtration and hardness of the water being used. Water, purified with reverse osmosis, for example, is more acidic than it was prior to treatment. Inversely, hard water is more alkali. This translates directly to the overall acidity of the final brew and it can easily be measured by a pH meter.