Espresso is a finely ground coffee that is brewed under pressure, à la minute. You know, espresso—essential to that morning habit of sitting in a crowded coffee shop, your hands wrapped around a cup of warm pleasure. Espresso and coffee culture is more important in our lives today than ever before.
Anatomy of a Shot
To begin, espresso is a beverage made by pressing a little amount of near-boiling water through finely-ground coffee.
When we make an espresso, the percolation of hot water through tightly packed and finely ground coffee extracts all of the components of the crushed coffee beans.
The pressurized water extracts soluble and insoluble particles, as well as oils, from the coffee beans and deposits them in the cup.
A shot of espresso has two layers: the crema and the liquid.
The crema layer is composed of carbon dioxide bubbles encased in water and oils. Crema typically comprises suspended coffee pieces as well as emulsified oils. This layer can be rather bitter, which is a good reason to stir your espresso before drinking it.
The liquid phase of the espresso is composed primarily of soluble solids, gases, and insoluble solids. This is the section that includes the majority of the delectable, rich flavors and fragrances that we enjoy in a wonderful cup of espresso.
