What is espresso?

The word espresso has been diluted by use to describe anything from furniture stain to brownie flavoring.  To coffee professionals, espresso is a beverage made to order under specific conditions. 

Here are the bare minimum conditions which need to be met in order to create the beverage espresso:

Espresso is a 1-1.5 ounces beverage that is prepared from 7-9 grams of coffee through which clean water of 192º - 202 F (88º - 92º C) has been forced at 9-10 atmospheres of pressure, where the grind of the coffee has made the brewing "flow" time approximately 20-30 seconds.

While brewing, the flow of Espresso will appear to have the viscosity of warm honey and the resulting beverage will exhibit a thick dark gold cream foam ("crema") topping. Espresso is usually prepared specifically for, and immediately served to its intended consumer.

--Specialty Coffee Association of America (SCAA)

 Learn more about espresso from these great resources...