the story of Gaggia

although brewed coffee beverages called espresso exist since the turn of the last century, it was not until the invention of the modern espresso machine by Achille Gaggia in 1948, that the modern espresso with crema, as we know it today, was born.

this design became less common from the mid 1960's on with the development of the pump machine.

lever machines have a design inherent pressure profile starting with pre-infusion of 1.3 bar and an initial extraction pressure of 9 bar which drops off towards 0 bar at the end of the extraction.

what does it mean:
 "It works without steam" and "natural creme coffee" ?

before 1948 espresso machines worked with higher boiler pressure (ca. 1.5 - 1.8 bar). the boiler pressure was utilized to press the brew water through the coffee puck. the extraction therefore happened under lower pressure but with overheated water (the water temperature being a function of pressure).
the result was a burnt beverage and occasional boiler explosions.
also, now there was the phenomena of 'crema' which confused customers. so Achille Gaggia had to do some marketing!