Espresso Coffee is an approach to extracting flavour from ground coffee beans. (other approaches being, French Press, Drip Filter, Stove Top etc…) The principle is to extract only the best and most flavoursome part, using filtered water which is not boiling, but is under a lot of pressure.
Essential understanding is that Espresso preparation is subjective
Our preference is to use follow the World Barista Championships definitions of espresso which states that:
“An espresso shot is a one ounce beverage, 30ml, plus or minus 5ml including crema. Prepared with various grams of coffee, depending on the coffee and the grind, through which clean water of 90.5 to 96 degrees C, has been forced at 8.5 to 9.5 atmospheres of pressure, and where the grind of the coffee is such that the brewing flow time is between 20 – 30 seconds.”