Diagram of how to use Aibao E61 Coffee Machine to drop Water Distribution Network

Diagram of how to use Aibao E61 Coffee Machine to drop Water Distribution Network

Another way to generate more pressure than 1.5 atmospheres is to use compressed air. For example, a home coffee machine in Milanes collector Ambrogio Fumagalli uses an air pump to pressurize hot water for brewing coffee (during World War II). In 1938, Francesco IIIy made the llletta' Coffee Machine, a large commercial coffee machine based on the principle of compressed air. When the crossbar on the coffee machine was lifted before World War II, water was injected into the space occupied by the piston and pressed down, and the pressure on the piston injected water evenly into the coffee powder in the filter. this means that hot water can brew coffee before it boils without scalding the coffee powder. At the same time, Achille Gaggia, the owner of a cafe in Milan, used a similar method to brew coffee. This method is gradually adopted by other coffee machine manufacturers, so this new coffee machine is also gradually replacing the steam pressure coffee machine. Today, the application of this principle can still be seen on household machines, the La Pavoni.

A brief history of coffee machine development Ⅲ

Before the second World War, although it avoided the disadvantage of using steam as a source of pressure to burn the coffee powder easily, because the pressure is to transmit the strength of the arm through the piston to push the hot water, not only a strong arm is needed, and the pressure is not easy to stabilize.

World War II stopped Cremonesi and Gaggia from improving the coffee machine. When Cremonesi died during the war, he left the patent for the coffee maker to his widow, Rosetta Scorza. We don't know whether Rosetta Scorza told Gaggia about the design patent, or whether Gaggia's design came entirely from its own invention. In 1947, Gaggia improved the original piston principle, and the force of the piston was controlled by a spring. As long as the operator presses the rod, the spring will be compressed and hot water will be injected into the space between the piston and the coffee powder. When the spring on the piston expands, press the piston down, the hot water will flow to the coffee place, and the rod will return to its original position.

In 1948, Gaggia applied this principle to complete his coffee machine, because he pushed hot water into a denser coffee powder and the pressure was greater and more stable than ever before, resulting in a layer of Krima on the coffee, which appeared for the first time in history. Since then, Klima has become the symbol of Italian coffee, and like Turkish coffee in the past, Klima is also the standard to judge whether coffee is good or bad. Gaggia's coffee machine also makes the brewing process more dramatic, with the arm operating the crossbar and the crossbar slowly returning to its original position, which has become a routine at many Espresso bars.

The household La Pavoni still maintains the tradition of Signore Cremonesi and does not add a spring to the piston, but some coffee machines on the market that are very similar to La Pavoni, such as the Elektra (Family series), add springs to make the pressure stronger and more stable. The method of discrimination is very simple, as long as you gently press the crossbar to see if there is any reaction force of the spring.