Classic Espresso machine
Classic Espresso machine
Drive mechanism Classic Espresso machine
Since their invention in 1901, multiple machine designs have been created to produce espresso. Several machines share some common elements.
Varying the fineness of the grind, the amount of pressure used to tamp the grinds, or the pressure itself can be used to vary the taste of the espresso. Some baristas pull espresso shots directly into a pre-heated demitasse cup or shot glass, to maintain a higher temperature of the espresso.
An espresso machine may also have a steam wand which is used to steam and froth liquids, to include milk, for beverages such as the cappuccino and latte.
Steam-driven Classic Espresso machine
A steam-driven unit operates by forcing water through the coffee by using steam or steam pressure. The first espresso machines were steam types, produced when a common boiler was piped to four group heads so that multiple types of coffee could be made at the same time. The design is still used today in low-cost consumer machines, as it does not need to contain moving parts. Many low-cost steam-driven units are sold in combination with a drip-coffee machine.
Piston-driven Classic Espresso machine
The piston, or lever, driven machine was developed in Italy in 1945 by Achille Gaggia, founder of espresso machine manufacturer Gaggia. The design generically uses a lever, pumped by the operator, to pressurize hot water and send it through the coffee grinds. The act of producing a shot of espresso is colloquially termed pulling a shot, because these lever-style espresso machines required pulling a long handle to produce a shot.
There are two types of lever machines; manual piston and spring piston design. With the manual piston, the operator directly pushes the water through the grounds. In the spring piston design, the operator works to tension a spring, which then delivers the pressure for the espresso (usually 8 to 10 bar).
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