Manual Lever Espresso Machines (more photos)
There are seriously old school and Lo-Fi machines, the first true espresso machines, orginally designed in 1945 by Achille Gaggia in Italy. They operate by using spring pressure to push the hot water through coffee grinds. Before manual lever was invented, steam-pressure was used which is so hot that it burns the grinds and does not have enough bars of pressure to qualify as actual espresso. In 1961 Feama invented the E61,the first motorized pump driven espresso machine, which is the most common type of machines in coffeehouses today.
However, the manual lever is making a comeback in artisan coffeehouse, because This is mainly due to the fact that these machines do a great job at preinfusion and pressure profiling, which has a great influence on the flavor extraction from freshly and lighter roasted beans. Some of the more famous 3rd-Wave coffeehouses using manual lever are Blue Bottle Coffee (SFO), Barefoot Coffee (SJC), Insight Coffee (SAC), and Cafecito Organico (LA).
A number of coffeehouses have refurbished classic La Marzocco manual lever machines, but a number of companies are still making them new. These include Victoria Arduino, Rancilio, Astoria, and La Povonia.
When using these for in a 3rd-Wave coffeehouse, it is wise to stick with the 3-4 group models and have a PID installed to insure greater temperature stability and control.