Espresso is a concentrated coffee beverage brewed by forcing hot water under high pressure through finely ground, dark roast coffee beans. Espresso is the base for many other popular coffee drinks, such as cappuccino, latte, mocha, and Americano.
The espresso brewing process begins with evenly grinding the coffee beans. The grind must be fine enough to allow water to flow through the grounds at high pressure, but coarse enough that the resulting brew is not overly bitter. Once the beans are ground, they are placed in a metal filter basket and inserted into an espresso machine.
Water is heated to just below boiling and forced through the grounds at high pressure (usually 9 bars). This process extracts more flavor from the beans than other brewing methods. As a result, espresso is strong and flavorful with a thick body and crema (a layer of reddish-brown foam on top).
Properly made espresso has a sweet taste and no bitterness. It should also have a thick body and creamy texture. The crema should be dense and smooth with small bubbles. If it is too light in color or dissolves quickly, this indicates that the espresso was not extracted properly.
Espresso making is both an art and a science. To make great espresso requires practice and understanding of how different variables impact the final product. The quality of the beans, grind size, water temperature, tamping pressure, extraction time, all play a role in creating perfect espresso shots