The act of producing a shot of espresso is often called "pulling" a shot, originating from lever espresso machines, with which a barista pulls down a handle attached to a spring-loaded piston, which forces hot water through the coffee at high pressure. Generally, one uses an espresso machine to make espresso. There is no universal standard defining the process of extracting espresso, but several published definitions attempt to constrain the amount and type of ground coffee used, the temperature and pressure of the water, and the rate of extraction.
The crema is produced by emulsifying the oils in the ground coffee into a colloid, which does not occur in other brewing methods. This process produces an almost syrupy beverage by extracting both solid and dissolved components. Tamping down the coffee promotes the water's even penetration through the grounds. Įspresso is made by forcing very hot water under high pressure through finely ground compacted coffee. The actual caffeine content of any coffee drink varies by size, bean origin, roast method and other factors, but a typical 28 grams (1 ounce) serving of espresso usually contains 65 milligrams of caffeine, whereas a typical serving of drip coffee usually contains 150 to 200 mg. Espresso is also the base for various coffee drinks-including caffè latte, cappuccino, caffè macchiato, caffè mocha, flat white, and caffè Americano.Įspresso has more caffeine per unit volume than most coffee beverages, but because the usual serving size is much smaller, the total caffeine content is less than a mug of standard brewed coffee. This preserves the strong coffee flavor present in the espresso. These oil droplets preserve some of the aromatic compounds that are lost to the air in other coffee forms. This characteristic of espresso contributes to what is known as the body of the beverage. The dispersion of very small oil droplets is perceived in the mouth as creamy. The second phase is suspended solids, while the third is the layer of gas bubbles or foam. The first dispersed phase is an emulsion of oil droplets. The three dispersed phases in espresso are what make this beverage unique. As a result of the pressurized brewing process, the flavors and chemicals in a typical cup of espresso are very concentrated. This is due to the higher concentration of suspended and dissolved solids, and the crema on top (a foam with a creamy consistency). It is also popular in Switzerland, Croatia, Bulgaria and Greece, and in Australia.Įspresso is generally thicker than coffee brewed by other methods, with a viscosity of warm honey. Espresso is the most common way of making coffee in southern Europe, especially in Italy, France, Spain and Portugal. Espresso coffee can be made with a wide variety of coffee beans and roast degrees. A cup of espresso from Ventimiglia, ItalyĮspresso ( / ɛ ˈ s p r ɛ s oʊ/ ( listen), Italian: ) is a coffee-brewing method of Italian origin, in which a small amount of nearly boiling water (about 90 ☌ or 190 ☏) is forced under 9–10 bars (900–1,000 kPa 130–150 psi) of pressure ( expressed) through finely-ground coffee beans.