Mercoledì 3 Feb 2010, 16:39

The method of coffee preparation that we call espresso originated at the end of the 19th century. The first espresso machine was presented at the Universal Exposition in Paris in 1855, developed to solve the slow speed and loss of flavor that occurred with other methods of coffee preparation. The goal was to develop a machine that prepared a cup of coffee in short time, that didn’t need to be kept warm. The word espresso means “pressed out,” referring to the brewing method.

To prepare one or two coffees to order, and quickly, the new machine forced hot (but not boiling) water through the coffee grounds under high pressure, initially delivered through steam that was controlled by a series of valves that were controlled by the bartender. In Italy, this became the most common way to make coffee, and eventually the word came to be used as a noun referring to the drink itself. In 1935, Francesco Illy substituted compressed air for the steam, thereby creating the first automatic machine, a prototype of the espresso machine used today. The invention of the spring piston lever machine and its subsequent commercial success changed espresso into the beverage we know of today, produced between 9 and 10 atmospheres, or bars, of pressure.

Full article on thenibble.com:
Expressly Espresso - Hot Facts About Coffee’s Strongest Brew