Espresso

History

Plate XV tells this story in two chapters (source 9). In Turin, Angelo Moriondo patents a machine in which steam pushes water through a cake of compressed coffee, in France in 1885 according to the historian Jonathan Morris, the drink being stored before being served (source 3). In Milan, Luigi Bezzera builds groups into which portafilters are tightened, to make a coffee expressly for a customer (source 3); his American patent, filed on June 10, 1902 and granted on April 28, 1903, is already assigned to Desiderio Pavoni (source 2).

Pavoni's Ideale, in 1905, is regarded as the first mass-produced machine (source 3); Ukers describes it in 1922 as an improvement, patented by Pavoni in 1907, of the Bezzera system introduced in 1903-1904, capable of 150 cups an hour (source 1). These machines pushed the water with steam: Morris describes a black, bitter, burnt coffee, coming out of a group at 130-140 °C under about 1.5 bars in 45 seconds, with no crema at all (source 3).

Crema is born when pressure separates from heat. After a crank piston by Achille Gaggia (1938), his patent of 1947, a lever-operated piston with gear and spring, passes the water under pressures that rise and fall between 3 and 12 atmospheres; oils and colloids then form the foam that Gaggia christens “coffee cream” (source 3). Gaggia dates his first patent, no. 365726, from September 5, 1938, for the Lampo machine, “lightning” (source 8). Gaggia's first lever machines, in 1948, are manufactured by Ernesto Valente, of Faema, and announce a natural crema obtained without steam (source 3).

Having fallen out with Gaggia, Valente fits in 1961 on the Faema E61 an electric pump controlled by a switch: mains water, put under pressure, crosses an exchanger before the group, and the machine serves one cup after another without waiting for the boiler (source 3). His patent, with an Italian priority of September 24, 1960, covers something else: a valve head that first lets the water wet the puck without pressure, the first valve opening at about 1.5 atmospheres and the second at about 7, because continuous-pressure machines leave no time to steep, unlike hand-operated pistons (source 4). This is pre-infusion.

The motion

The most precise quantified definition read is that of the Italian National Espresso Institute, founded on July 6, 1998: 7 g of grounds to within 0.5 g, water leaving the group at 88 °C to within 2 °C, 9 bars to within 1 bar, 25 seconds to within 2.5 seconds, 25 mL in the cup crema included, served at 67 °C, less than 100 mg of caffeine per cup; a counter rule of thumb, a good espresso flows at one milliliter per second (source 5).

The specialty counter has moved away from it. Cameron and his coauthors recall the historical definition of the American specialty coffee association, 7 to 9 g for 25 to 35 mL, at 92-95 °C, under 9 to 10 bars, in 20 to 30 seconds, and note that cafés commonly use 15 to 22 g for 30 to 60 g of drink (source 6).

The settings

• GrindVery fine; too fine, the puck clogs in places (source 6).
• Dose7 g to within 0.5 g for certified Italian espresso (source 5); 15 to 22 g in specialty cafés (source 6).
• Brew ratioAbout 1:3.6 for Italian espresso (7 g for 25 mL, calculated) (source 5); 20 g for 40 g, that is 1:2, in Cameron's test (source 6).
• Temperature88 °C to within 2 °C at the group outlet (source 5); 92 °C in Cameron's test (source 6).
• Time25 seconds to within 2.5 seconds (source 5); under 15 seconds with Cameron's method (source 6).
• Pressure9 bars to within 1 bar (source 5); Cameron worked at 6 bars, 9 bars clogging fine grinds (source 6).

What it has going for it

• It serves one cup on demand, prepared for each customer, which is what made the Italian counter (source 3).
• Pressure extracts a very concentrated drink quickly: more than 4% dry matter in the three espressos of Gloess's test, against about 1.3% for the long coffees (source 7).
• Crema, a foam of oils and colloids born of pressure, gives a texture that no gravity method achieves (source 3).

What is held against it

• Grinding too fine clogs zones of the puck: the yield drops, the cup becomes both bitter and sour, and coffee is wasted (source 6).
• The window for success is narrow: according to the Italian institute, fifteen seconds give a coffee lacking body and more bitter, thirty-five seconds woody and sharp notes (source 5).
• It takes a machine, an adjustable grinder and a setting revised through the day (source 9).

What it gives in the cup

In Gloess's test, all the espressos have a marked roasted and bitter note, a pronounced body and a long aftertaste; the panel links dry matter to body, caffeine and chlorogenic acids to bitterness (source 7). The Italian institute expects a hazelnut-brown to dark-brown crema, with tawny highlights, of very fine texture (source 5). A single yield does not tell everything: Cameron obtains two espressos at 22% with two grinds whose composition cannot be the same, and concludes that the barista must taste (source 6).

Variants play on the water. The ristretto, “restricted” in Italian, is a short espresso of about 15 mL; Morris makes it the preference of the south of Italy, where the shorter extraction reduces the bitterness of blends richer in canephora and the amount of caffeine (source 3). The lungo, “long,” pushes more water: in Gloess's test, the 120 mL long coffees pull more from the coffee per gram than the espressos, but at a concentration of about 1.3%, with slightly less intensity (source 7). The Italian institute points out that a short coffee of 15 mL or a long coffee of 35 mL is no longer an Italian espresso (source 5).

Anecdotes

• The Caffè Manaresi of Florence, opened in 1898 and reputed to be the first American-style bar in Italy, where one drinks standing at the counter, was nicknamed by Florentines the café of the standing people (source 3).
• The word “barista” appears in the late thirties, probably with the Fascist campaign to Italianize foreign words; until then, the counter was run by a barman (source 3).

The sources for this sheet

1. William H. Ukers, All About Coffee, New York, The Tea and Coffee Trade Journal Company, 1922, chapters XXXIV and XXXVI and chronology (UTF-8 transcription from the local library): Pavoni 1907, Bezzera system 1903-1904, Ideale machine · online · primary
2. Luigi Bezzera, US patent 726,793, “Coffee-making machine,” filed June 10, 1902, granted April 28, 1903, assigned to Desiderio Pavoni · online · primary
3. Jonathan Morris, “Making Italian Espresso, Making Espresso Italian,” Food and History, vol. 8, no. 2, 2010, p. 155-183, DOI 10.1484/J.FOOD.1.102222 (author's preprint, University of Hertfordshire) · online · academic
4. Ernesto Valente, US patent 3,230,974, “Alternately seating valves,” Italian priority of September 24, 1960 (16,620/60), filed September 25, 1961, granted January 25, 1966 · online · primary · reading: yes (image of the specification)
5. Istituto Nazionale Espresso Italiano, Espresso Italiano Certificato, brochure in English (archived copy of August 10, 2012) · online · institutional
6. Michael I. Cameron, Christopher H. Hendon, Jamie M. Foster et al., “Systematically Improving Espresso: Insights from Mathematical Modeling and Experiment,” Matter, vol. 2, no. 3, 2020, p. 631-648, DOI 10.1016/j.matt.2019.12.019 · online · academic
7. Alexia N. Gloess et al., “Comparison of nine common coffee extraction methods: instrumental and sensory analysis,” European Food Research and Technology, vol. 236, 2013, p. 607-627, DOI 10.1007/s00217-013-1917-x · online · academic
8. Gaggia, “Our history,” accessed October 21, 2026 (manufacturer) · online · manufacturer
9. PXL Roasters, plate XV “Preparations,” sections 10 and 11, Espresso (preparations-10.html, preparations-11.html), revision of September 24, 2026 · internal