What is one reason espresso is brewed under pressure?

Espresso is brewed under pressure primarily to enhance flavor concentration. When water is forced through finely-ground coffee at high pressure, it extracts a greater amount of oils and soluble compounds from the coffee grounds in a much shorter period than traditional brewing methods. This process creates a shot of espresso that is rich in flavor and has a distinct crema on top, which contributes to both the aroma and the overall drinking experience.

The high pressure also helps to emulsify the coffee oils, intensifying the body of the espresso and capturing more aromatic compounds than would be achieved by brewing without pressure. The result is a concentrated brew that showcases the complex flavors of the coffee beans, leading to a more vibrant and dynamic taste profile.

While other options, like increasing bitterness or reducing preparation time, may have some influence in a broader sense, they do not capture the primary purpose of brewing espresso under pressure, which is to maximize flavor extraction and concentration. Caffeine extraction is also not significantly decreased; in fact, espresso typically has a higher caffeine content per ounce compared to regular brewed coffee, although the smaller serving size means a typical serving may contain less caffeine overall.