The first espresso machines made coffee that tasted burnt and had no crema
Milan's first commercial espresso machines, sold from 1905, could turn out 1,000 cups an hour, but their steam pushed at only about 1.5 bars and scorched the coffee. Crema, the tan foam now seen as espresso's signature, arrived only in 1947, when Achille Gaggia's lever-driven piston raised the pressure to 12 atmospheres.
Italians spent the late 19th century trying to speed up café service. In 1884 Angelo Moriondo of Turin patented a steam-driven machine that controlled steam and water separately, possibly the earliest espresso machine, though it brewed in bulk. Luigi Bezzera of Milan filed a patent in 1901 for a boiler feeding several group heads, each fitted with a portafilter of packed coffee, so a cup could be made to order. Desiderio Pavoni bought those patents in 1903, added a pressure-release valve and began selling machines in 1905. Their shots took nearly a minute, about twice as long as today's.
For thirty years the machines were luxury kit. Sales were largely confined to Milan at first, then spread with standing bars and with soldiers who picked up a coffee habit from World War I rations. By the 1920s their Art Deco styling made them symbols of modern living, helped by the marketing of Pier Teresio Arduino. Consumption peaked in 1929, then fell under fascist curbs on luxuries and the Depression until coffee imports stopped entirely in 1941.
The breakthrough was pressure without steam. Francesco Illy patented a compressed-air machine in Trieste in 1935, and Gaggia a hand-pulled piston in 1938; his 1947 design forced water through the coffee puck hard enough to emulsify oils into foam, and he sold the result as crema caffè. In 1961 Ernesto Valente's Faema E61 replaced muscle with an electric pump delivering 9 bars, drew water straight from the mains, and was cheap enough to spread just as much of Italy was getting electricity.
A typical shot is 25 to 30 ml pulled in about 25 to 30 seconds. It holds more caffeine per millilitre than drip coffee but less per cup, roughly 65 mg against about 95 mg in a larger mug. Espresso does not have to be made from dark-roast beans; that belief is a myth. In Italy it is simply called caffè.
Source: Espresso
