EM 4.12 Recap and Glossary
- The E66 by Faema was the first machine to have adjustable volumetric controls.
- The first use of electronic flow-meters in an espresso machine was described in a 1978 patent lodged by Rancillio. Their 1978 patent describes a flow-meter very similar to the kind used on modern machines, with a pair of magnets mounted on an impeller that spins as the water flows past it.
- The advent of electronic controllers in espresso machines from the 1980s onwards paved the way for much more precise and complex control of espresso machines.
- In the 1990s, Seattle café owner David Schomer was extremely vocal in calling out traditional manufacturers for their failure to achieve temperature stability. He published his theories in a column in Café Olé magazine in the ’90s and in his 1996 book Espresso Coffee: Professional Techniques.
- Schomer’s book convinced many users of the influential alt-coffee forum of the importance of temperature stability. In February 2001, Schecter posted on the alt-coffee forum about his successful attempt to install a PID controller on his Rancilio Silvia prosumer espresso machine.
- Because a PID varies the amount of power used, the heating elements do not have to run at their maximum energy output for long periods.
- In 2001, the Dalla Corte company of Milan, Italy, built the Evolution, which featured an independent PID-controlled brew boiler in the top of each group head.
- In 2004, Scace produced the Scace Thermofilter for measuring the temperature at the group head, which gave rise to a widespread awareness of the successes and failures of different machines.
- In 2012, the Simonelli Aurelia II, by Nuova Simonelli, achieved a temperature stability of ∓0.1°C.
- In 2017, La Marzocco redesigned the classic lever mechanism to make it safer and more temperature stable, with a PID-controlled heating element embedded into the bayonet ring of each group.
- To achieve temperature stability at the group head, Decent Espresso combines 110°C (230°F) water with room temperature water just before the water mixture enters the group.