Espresso is the name of a highly concentrated, bittersweet coffee originating in Italy in the early 20th century. Translated from Italian, the word espresso refers to the speed and single-serve nature of the coffee compared with slower and more communal methods of brewing coffee^[1]. Each shot of espresso is made to order upon customer request, as opposed to being brewed in anticipation of demand. Typically served in a demitasse cup or used with other ingredients to create another beverage such as a cappuccino or a caffè corretto, espresso has become representative of coffee culture in many coffee-consuming regions.

Contents 1 Characteristics 2 Making Espresso 3 History 4 References 5 Comments

CharacteristicsEdit

While the taste of espresso will vary widely depending on the coffee (including the roast), the quality of grind, and technique used to brew it, a well-made espresso will generally have a heavy body, rich texture, and a bittersweet taste. Each shot should have a layer of crema (foam) on the surface, generally golden to dark tan in color. A single shot of espresso is generally made with seven to eight grams of ground coffee and results in between one to one and a half ounces of coffee. This ratio represents a highly concentrated coffee, containing more caffeine per volume and generally considered to be stronger than drip brewed coffee.

Making EspressoEdit

There are several types of espresso-based beverages, but all are based on one or more shots of pure espresso. Espresso is brewed in some sort of espresso machine which "presses" hot water through a dense puck of finely ground medium to dark roasted coffee.

HistoryEdit

The rise of espresso as a popular coffee has paralleled technological advances to the espresso machine during the 20th century. Still, earlier forms of coffee brewing gave rise to the modern espresso. Much like espresso, coffee brewed in an Ibrik (or related brewer) was dark roasted, unfiltered, thick, and bittersweet. Additionally, when brewed correctly, this coffee has a layer of foam much like the crema of espresso. Traditionally served strong and sweet, coffee in the Middle East and Southeastern Europe was a natural step toward the technicalogical developments which would give rise to modern espresso^[2].

In 1901, Luigi Bezzera patented what is considered to be the design for the first espresso machine. It was based on the principle of earlier coffee makers (similar to a moka pot) which used steam pressure to push water into an area from which it would be pressed by the force of gravity through the coffee and into a reservoir. Bezzera's system, however, would use the pressure from the steam to force the hot water directly through the coffee and into the cup. His design allowed for serving freshly brewed coffee to customers on demand. Bezzera would sell this patent to Desiderio Pavoni, who, in 1905, would begin manufacturing the espresso machines for sale. Other Italian manufactures would soon follow suit^[3].

Early espresso machines were large and ornate, using gas as their heat source. They consisted of large, cylindrical reservoirs turned on their end, with several spouts, valves, and gauges protruding from the front and sides. Finally, the espresso machines were topped with an ornate figurehead, most often an eagle^[4].

These early machines were limited to the amount of pressure that could be produced by the steam alone--around one and a half atmospheres (meaning one and half times the pressure exerted by the earth's atmosphere), not high enough to allow for full extraction of the coffee oils or use a heavily packed puck of coffee. Higher steam pressure could be generated from using more heat, but the hotter water caused the coffee grounds to become overheated as well, damaging the taste of the resulting cup.

In 1947, Achille Gaggia developed a modification to espresso machines which, instead of using steam pressure to drive the water through the coffee, used a manually pulled lever to cause a piston to press the hot water through the coffee. The higher pressure generated through this method allowed for a much tighter packed puck of coffee and a more full extraction of the coffee's flavors. Additionally, through this method, the signature crema that floats at the top of a properly prepared espresso was first born^[5]. Despite continuing improvements, modern espresso makers are still mostly based upon Gaggia's model^[6].

One of the drawbacks to the Gaggia machine was that both the water for the espresso and the steam were heated in the same tank. The water would heat slowly, and would become stale over time, affecting the quality of the resulting espresso. In 1961, the FAEMA company (Fabbrica Apparecchiature Elettromeccaniche e Affini or, in English, factory producing electrical and mechanical equipment and similar) developed the E61, a machine which would heat water for use in brewing the espresso by passing it through the tank of older water before it got to the brew head. The fresh water would never interact with the older water, which would be reserved for use only in the production of steam. Other improvements in the E61 included an electric-driven pump, a mechanism for decalcifying water (so as to not to contaminate the machine with deposits), and the ability to circulate water through the group head so that it would reach a warm temperature prior to brewing without having to run water through it first^[7].

ReferencesEdit