Espresso machine

Angelo Moriondo, from Turin, patented a steam-driven "instantaneous" coffee beverage making device in 1884 (No.

33/256 dated 16 May 1884 (according to the "Bollettino delle privative industriali del Regno d'Italia", 2nd Series, Volume 15, Year 1884, pp.

Seventeen years later, in 1901, Luigi Bezzera, from Milan, devised and patented several improvements to the espresso 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.

The design generically uses a lever, pumped by the operator, to pressurize hot water and send it through the coffee grounds.

Four variants exist in home machines, depending on how brew water and steam are boiled; in discussion these are generally known by acronyms.

During the process of extracting a shot of espresso, hot water is forced through the grouphead under pressure.

[7] A portafilter (or group handle) attaches to the grouphead of semi-automatic and piston-driven espresso machines, and carries a tamped puck of coffee grounds within its basket.

The portafilter forms a seal with the espresso machine's gasket, and directs high-pressure hot water through the coffee puck.

A bottomless portafilter is one tool baristas use to analyze the quality of the coffee grind and the evenness of the extraction and allows for a visual check of "channeling" or the condition in which water is able to pierce a hole in the espresso puck during the brew process leading to poor extraction.