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How Espresso Works


What is Espresso?
Simple camping-style espresso machine. When the water is heated over a fire, pressure builds inside the vessel, and the only way for it to escape is up the tube, through the coffee and out of the tube in the top. Since the end of the tube is under water, the pressure forces the hot water up through the tube.
Simple camping-style espresso machine. When the water is heated over a fire, pressure builds inside the vessel, and the only way for it to escape is up the tube, through the coffee and out of the tube in the top. Since the end of the tube is under water, the pressure forces the hot water up through the tube.

­Espresso does not refer to a particular type of bean, but rather a process of extracting the flavor from ground coffee beans by a combination of not-quite-boiling-hot water and pressure. The word can also refer to the product resulting from this process -- as in "I'll have a cup of espresso, please."

Pronounced ess-press-o, not eX-press-o, espresso is an Italian word, shortened from caffè espresso. Although many people believe the word espresso is an adaptation or translation of Italian for "express"(as in "fast") because espresso is made and served immediately, that's not the case. It's actually the past participle of the word esprimere, which means, "to express" or "to press out." So caffè espresso literally means "pressed-out coffee." Espresso is generally attributed to originating in Italy around the 1900s, when Luigi Bezzera filed a patent for a machine that forced boiling water and steam through coffee grind into a cup.

In Italy, good espresso brewing is defined by "the four Ms:"

  • Miscela
  • Macinazione
  • Macchina
  • Mano

This loosely translates in English to:

  • Blend or mix of coffee beans
  • The grind or grinding process
  • The machine
  • The person making the espresso

In order to understand the espresso phenomenon, it's important to have an understanding of the espresso experience. Almost all espresso afficionados will tell you that flavor is key. The appreciation of a good cup of espresso is more about flavor, which is a melding of the aroma and taste of the espresso, rather than just the taste alone. To prove this to yourself, hold your nose the next time you drink espresso. You will taste the bitterness of the caffeine, but you will not experience the full flavor of the coffee, which is a characteristic of smell.

Let's take a closer look at the defining elements that can create the perfect espresso experience.


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