How does Guinness on tap work?

Answered by James Porterfield

Guinness on tap is a unique and beloved that has gained a reputation for its smooth, creamy texture and iconic tight head. The secret behind this distinctive pour lies in the way Guinness is served using a specialized draft beer system.

Unlike traditional beers, Guinness utilizes a blend of nitrogen and carbon dioxide (CO2) gas to push the beer through the lines and into the glass. This nitrogen/CO2 blend is what gives Guinness its characteristic creamy head, making it instantly recognizable to beer enthusiasts worldwide.

The process begins with a specific gas blend contained in a nitrogen gas tank, which typically consists of 75% nitrogen and 25% CO2. This blend is crucial in achieving the desired texture and appearance of the beer. The tank is connected to the draft beer system, where the gas is introduced into the lines leading to the tap.

When a bartender pours a pint of Guinness, the beer travels through these specially designed lines. As it does, the nitrogen gas is released, creating tiny bubbles that give the beer its velvety texture. This is in contrast to the larger bubbles formed by CO2 alone, which result in a more carbonated and effervescent beer.

As the beer reaches the tap, it passes through a restrictor plate or disc. This plate helps control the flow and pressure of the beer, ensuring a steady and controlled pour. The restrictor plate also creates turbulence in the beer, allowing the nitrogen bubbles to further develop and contribute to the creamy head.

The tap itself is designed with a special nozzle that helps to agitate the beer as it is poured. This agitation aids in the formation of the nitrogen bubbles, creating a cascading effect and ultimately resulting in the signature Guinness head. The tap handle is also typically pushed forward instead of pulled back, as this helps to further enhance the creamy texture and maintain the integrity of the pour.

The final result is a pint of Guinness with a rich, dark appearance and a smooth, velvety mouthfeel. The nitrogen bubbles give the beer a creamy texture that lingers on the palate, enhancing the overall drinking experience. The tight head, formed by the nitrogen gas, not only adds to the visual appeal of the beer but also helps to retain the aroma and flavors, ensuring that every sip is as enjoyable as the first.

It is worth noting that the use of nitrogen in the draft system is just one aspect of what makes Guinness unique. The beer itself is brewed with a combination of roasted barley, which imparts its distinctive dark color and rich flavors. The nitrogen/CO2 blend simply complements these characteristics and enhances the overall drinking experience.

Guinness on tap is served using a specialized draft beer system that utilizes a blend of nitrogen and CO2 gas. This unique gas blend, along with the design of the lines, taps, and restrictor plates, contributes to the creamy, tight head and smooth mouthfeel that Guinness is known for. It is this attention to detail and dedication to quality that has made Guinness a beloved beer around the world.