Espresso

Espresso is generally thicker than coffee brewed by other methods, with a viscosity similar to that of warm honey. This is due to the higher concentration of suspended and dissolved solids, and the crema on top (a foam with a creamy consistency).[3] As a result of the pressurized brewing process, the flavors and chemicals in a typical cup of espresso are very concentrated.

Espresso contains more caffeine per unit volume than most coffee beverages, but as its usual serving size of 25–30 ml (1 US oz) is much smaller than for other coffee drinks, the overall caffeine content of a single serving of espresso is generally lower than that of other coffees.[4] While the exact caffeine content of any coffee drink will vary, a typical 30 millilitres (1 US fluid ounce) serving of espresso contains approximately 65 milligrams of caffeine, but a typical 240 millilitres (8 US fluid ounces) serving of drip coffee contains between 150 and 200 mg of caffeine.[5][6][7]

The three dispersed phases in espresso are what make this beverage unique. The first dispersed phase is an emulsion of oil droplets. The second phase is suspended solids, while the third is the layer of gas bubbles or foam. The dispersion of very small oil droplets is perceived in the mouth as creamy. This characteristic of espresso contributes to what is known as the body of the beverage. These oil droplets preserve some of the aromatic compounds that are lost to the air in other coffee forms, enhancing the strong flavor of espresso.[8]

Espresso is served on its own, and is also used as the base for various other coffee drinks, including caffè latte, cappuccino, caffè macchiato, caffè mocha, flat white, and caffè Americano.

Espresso brewing

Finely-ground coffee for espresso

Espresso is made by forcing very hot water under high pressure through finely ground compacted coffee. There is no universal standard defining the process of extracting espresso,[9] 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.[10][11] Generally, one uses an espresso machine to make espresso.

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. However, it is more common for an electric pump to generate the pressure.[12]

Tamping down the coffee promotes the water's even penetration through the grounds.[13] This process produces a thicker beverage by extracting both solid and dissolved components.

The "crema" is a layer of dense foam that forms on top of the drink.[14][15] It consists of emulsified oils in the ground coffee turned into a colloid, which does not occur in other brewing methods. Crema is produced when water, placed under very high pressure, dissolves more carbon dioxide, a gas present inside the coffee that is produced during the roasting process.[16]

The technical parameters outlined by the Italian Espresso National Institute for making a "certified Italian espresso" are:[17]

Espresso is both a coffee beverage and a brewing method. It is not a specific bean, bean blend, or roast level. Any bean or roasting level can be used to produce authentic espresso. For example, in southern Italy, a darker roast is generally preferred. Farther north, the trend moves toward slightly lighter roasts, while outside Italy a wide range is popular.[18]

Angelo Moriondo, inventor of an important precursor to the espresso coffee machine. Luigi Bezzera and the first espresso machine at the World Expo 1906 in Milan.

A manual Italian handmade espresso machine

An automatic Italian handmade espresso machine

The first coffee machine was created in France in 1822 by Louis Bernard Rabaut.[19][20]

In 1855, another Frenchman, Edouard Loysel de Santais, presented a café express machine able to make 2000 cups of coffee in one hour, however the machine did not use steam to directly force water through the coffee and it apparently brewed coffee into a pot.[21][22]

Angelo Moriondo is often erroneously credited for inventing the beverage, since he patented a steam-driven coffee beverage making device in 1884 (No. 33/256), probably the first Italian coffee machine similar to other French and English 1800s steam-driven coffee machines. The device is "almost certainly the first Italian bar machine that controlled the supply of steam and water separately through the coffee" and Moriondo is "certainly one of the earliest discoverers of the expresso [sic] machine, if not the earliest".[23] Seventeen years later, in 1901, Luigi Bezzera, from Milan, devised and patented several improved versions of the coffee machine, the first of which was applied for on 19 December 1901. Titled "Innovations in the machinery to prepare and immediately serve coffee beverage"; Patent No. 153/94, 61707, was granted on 5 June 1902, and was the first espresso machine.[24] In 1903, the patent was bought by Desiderio Pavoni, who founded the La Pavoni company and began to produce the machine industrially, manufacturing one machine daily in a small workshop in Via Parini, Milan.[25]

A detailed discussion of the spread of espresso is given in (Morris 2007). In Italy, the rise of espresso consumption was associated with industrialization and urbanization, notably in Turin, Genoa, and Milan in northwest Italy. Italians also spread espresso culture into their East African colonies, Italian Somalia and Italian Eritrea.[26] Under the Fascist regime, coffee consumed standing up was subject to price controls, encouraging the "stand at a bar" culture.

In the English-speaking world, espresso became popular, particularly in the form of cappuccino, owing to the tradition of drinking coffee with milk and the exotic appeal of the foam; in the United States, this was more often in the form of lattes, with or without flavored syrups added. The latte is claimed to have been invented in the 1950s by Italian American Lino Meiorin of Caffe Mediterraneum in Berkeley, California, as a long cappuccino, and was then popularized in Seattle,[27] and then nationally and internationally by Seattle-based Starbucks in the late 1980s and 1990s.

In the United Kingdom, espresso grew in popularity among youth in the 1950s, who felt more welcome in the coffee shops than in pubs. Espresso was initially popular, particularly within the Italian diaspora, growing in popularity with tourism to Italy exposing others to espresso, as developed by Eiscafès established by Italians in Germany. Initially, expatriate Italian espresso bars were seen as downmarket venues, serving the working-class Italian diaspora and thus providing appeal to the alternative subculture; this can still be seen in the United States in Italian American neighborhoods, such as Boston's North End, New York's Little Italy, and San Francisco's North Beach. As specialty coffee developed in the 1980s (following earlier developments in the 1970s and even 1960s), an indigenous artisanal coffee culture developed, with espresso instead positioned as an upmarket drink.

In the 2010s, coffee culture commentators distinguish large-chain mid-market coffee as "Second Wave Coffee", and upmarket artisanal coffee as "Third Wave Coffee". In the Middle East and Asia, espresso is growing in popularity, with the opening of Western coffee-shop chains.[28]

Trieste is the seat of the Università del Caffè, founded by Illy in 1999. This center of excellence was created to spread the quality coffee culture through training across the world, educate barista, and conduct research and innovation. Particular attention is paid to the preparation of the espresso and the relevant scientific research. It is also about the correct interaction of coffee and espresso machine.[29]

Café vs. home preparation

A home espresso machine

See also: Espresso machine

Home espresso machines have increased in popularity with the general rise of interest in espresso. Today, a wide range of home espresso equipment can be found in kitchen and appliance stores, online vendors, and department stores. The first espresso machine for home use was the Gaggia Gilda.[30] Soon afterwards, similar machines such as the Faema Faemina, FE-AR La Peppina and VAM Caravel followed suit in similar form factor and operational principles.[31] These machines still have a small but dedicated share of fans. Until the advent of the first small electrical pump-based espresso machines such as the Gaggia Baby and Quickmill 810, home espresso machines were not widely adopted. In recent years, the increased availability of convenient counter-top fully automatic home espresso makers and pod-based espresso serving systems has increased the quantity of espresso consumed at home. The popularity of home espresso making parallels the increase of home coffee roasting. Some amateurs pursue both home roasting coffee and making espresso.

In a 100 ml (grams, 3.5 oz) reference amount, espresso has significant levels of dietary mineral magnesium, the B vitamins niacin and riboflavin, and around 212 mg of caffeine per 100 grams of liquid brewed coffee (table).

Some English dictionaries translate espresso as "pressed-out",[32] but the word also conveys the senses of expressly for you and quickly:

The words express, expres and espresso each have several meanings in English, French and Italian. The first meaning is to do with the idea of "expressing" ("pressing out of") or squeezing the flavour from the coffee using the pressure of the steam. The second meaning is to do with speed, as in a train. Finally there is the notion of doing something "expressly" for a person ... The first Bezzera and Pavoni espresso machines in 1906 took 45 seconds to make a cup of coffee, one at a time, expressly for you.[33]

Modern espresso, using hot water under pressure, as pioneered by Gaggia in the 1940s, was originally called crema caffè (in English, "cream coffee") as seen on old Gaggia machines, due to the crema.[34] This term is no longer used, though crema caffè and variants (caffè crema, café crema) still appear in branding.

An Italian-American espresso shop

Extracting a doppio

A double ristretto with the first half of the shot in the glass at the bottom of the image, and the second half in the glass on the right

The main variables in a shot of espresso are the "size" and "length".[48][49] This terminology is standardized, but the precise sizes and proportions vary substantially.

Cafés may have a standardized shot (size and length), such as "triple ristretto",[49] only varying the number of shots in espresso-based drinks such as lattes, but not changing the extraction – changing between a double and a triple requires changing the filter basket size, while changing between ristretto, normale, and lungo may require changing the grind, which is less easily accommodated in a busy café.

In addition to being served alone, espresso is frequently blended, notably with milk – either steamed (without significant foam), wet foamed ("microfoam"), or dry foamed, and with hot water. Notable milk-based espresso drinks, in order of size, include: macchiato, cappuccino, flat white, and latte; other milk and espresso combinations include latte macchiato, cortado and galão, which are made primarily with steamed milk with little or no foam. Espresso and water combinations include Americano and long black. Other combinations include batch-brewed coffee with espresso, sometimes called "red eye" or "shot in the dark".[51]

• 
  Espresso macchiato
• 
  Lungo
• 
  Americano
• 
  Cappuccino
• 
  Caffè latte
• 
  Latte macchiato

Other variants:

• Ristretto – "condensed" espresso to approximately 20 ml, brews in the lever for a shorter time than espresso.
• Caffè crema – "long" espresso from more water and coarser ground coffee, approximately 120–180 ml
• Espresso con panna – espresso with cream
• Viennese coffee – lungo with whipped cream
• Long black – Australian version of Americano
• Café mocha – cafe latte with chocolate
• Espresso martini – espresso with coffee liqueur and vodka
• Caffè corretto – (it. corrected coffee) espresso with brandy, grappa or sambuca

Methods of preparation differ between drinks and between baristas. For macchiatos, cappuccino, flat white, and smaller lattes and Americanos, the espresso is brewed into the cup, then the milk or water is poured in. For larger drinks, where a tall glass will not fit under the brew head, the espresso is brewed into a small cup, then poured into the larger cup; for this purpose a demitasse or specialized espresso brew pitcher may be used. This "pouring into an existing glass" is a defining characteristic of the latte macchiato and classic renditions of the red eye. Alternatively, a glass with "existing" water may have espresso brewed into it – to preserve the crema – in the long black. Brewing onto milk is not generally done.

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Citations

Sources

• Davids, Kenneth (2013). Coffee: A Guide to Buying, Brewing, and Enjoying (5 ed.). St. Martin's Press. ISBN 978-1466854420.
• Fumagalli, Ambrogio (1995). Coffee Makers. Chronicle Books. ISBN 0-8118-1082-8.
• Illy, Andrea; Viani, Rinantonio (2005). Espresso: The Science of Quality. Academic Press. ISBN 0-12-370371-9.
• Illy, Francesco; Illy, Riccardo (1989). The Book of Coffee. Milano: Abbeville Press. ISBN 1-55859-321-7.
• Schomer, David C. Espresso Coffee: Professional Techniques. 1996.

• The dictionary definition of espresso at Wiktionary
• Media related to Espresso at Wikimedia Commons