Mirage Idrocompresso - Features
• In 1947 Giovanni Achille Gaggia put down his patent for a spring loaded piston group, operated by a lever, on an espresso machine. With this system for the first time the water was pushed through the ground coffee under a high pressure. This was the birth of “crema” on top of the coffee.

•Since that year many thousands of espresso machines have been equipped with this group. Right up to this day the system has many dedicated fans. In Turin and Naples almost 90% of the espresso machines are still levergroup-machines, also in shops turning over 10—12 kilos a day. Lately more and more people seem to discover these machines again, re-newed interest is clearly growing. The theatrical effect of these levers moving up and down surely contributes to the attraction.

• The levergroup consists of a large vertical cylinder, with an up and down movable piston inside. On top of this piston sits a very strong spring. By pulling the lever down the piston moves up, thereby compressing the spring. When the piston is at its highest position one or more holes are cleared. From these hot water flows under a low pressure into the space under the piston, on top of the coffee in the filterbasket.
The space between underside of piston and shower screen holds the amount of two espressos: 60 cc.
A column of water now sits on top of the coffee, creating a slow, evenly spread and thorough infusion.
When the lever is released, the strong spring starts to push the piston down, forcing the water through the coffee. Simultaneously the lever slowly returns to its upward position. When the piston has arrived at its lowest point, the extraction process has stopped automatically and the lever has returned to its original starting position. During this extraction process the pressure varies from high to slightly lower towards the end of the process, as the spring relaxes.
It is a totally silent process, no clicking solenoids or humming pump motor.

• The coffee puck is very dry, as all water only goes downwards, there is no need for a pressure-relief from above the coffee. This also means no cleaning by back-flushing is needed.

• The absence of group-solenoids, pump and most electronic controls makes this a very reliable and easy to service espresso machine.

• The Mirage Idrocompresso uses the heat-exchanger loop to heat the group and to deliver hot water onto the coffee. It does not use water out of the main boiler.

• Just as the normal Mirage, the Idrocompresso can be built as Duette or Triplette, with Classic or Veloce bodywork.