Extraction methods Espresso

Espresso is probably one of the most popular hot beverages, and not only in Italy.

However, it is an Italian to whom the credit goes for this extraordinary invention: Angelo Moriondo presented the first espresso machine at the 1884 General Exposition in the Valentino Park, Turin.

From this first great revolution (and a number of further evolutionary steps) Faema of Italy, in 1961, made the first machine to offer continual supply. The E61 used a volumetric pump to force the water through the coffee bed at the ideal pressure for preparing an espresso of 9 atmospheres and so replaced earlier lever-operated machines.

This date marked a historic moment in the preparation of coffee, as for the first time clearly-defined parameters were now available when preparing an espresso.

Espresso, by definition, is made on the spot and made quickly.

The espresso machine pump exerts a pressure of 9 atmospheres on the ground coffee and at this pressure the water can dissolve and emulsify the fats and fibres and so create the famous espresso crema.

The Specialty Coffee Association’s preparation parameters are, quite rightly, not too tightly defined as espresso preparation changes from culture to culture.

The indicative values are from 7 to 10 g of ground coffee for a “single shot” with an extraction time of between 20 and 30 seconds to obtain 15 g of beverage in the cup.

For a supremely good espresso, excellent raw material is fundamental to a perfect example, but there are also some basic steps and parameters that every barista and Coffee Chef must never forget and that every coffee lover should be aware of and expect.

  • Clean the portafilter of any leftover residue;
  • Clean the shower after each use under gentle running water, a process known as “flushing”;
  • Check the correct amount of ground coffee in the portafilter;
  • Correct tamping pressure of the coffee bed inside the portafilter;
  • Don’t wait, start coffee preparation as soon as the portafilter is inserted.

Finally, something that is equally fundamental and indispensable should not be forgotten: the water used. This is integral to coffee extraction and is just as important as the blend used, especially when you consider that each cup of espresso is more than 90% water.

The use of filtered water when making espresso is a rule that no barista should ever forget: a good filtration system provides high quality water with a balanced mineral content and also prevents the formation of limescale deposits inside the machine which could compromise such vital parameters as water flow and temperature.

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