Espresso coffee is a beverage which is created by forcing liquid hot water through coffee beans which have been roasted and crushed into small particles, and this has to be done under high pressure. A standard time for a single shot of expresso takes up to around 25 to 30 seconds to brew. Modern espresso machines usually operate with around 9 bars of pressure which is equivalent to around 90 meters underwater. The water temperature can usually range from around 92° to 96° Celcius which translates to around 190° to 195° in Fahrenheit. The golden foam that’s located on the top of the expresso drink has it’s own name and is called crema, which forms from emulsified coffee oils and carbon dioxide released during extraction.
The name “Espresso” is not a specific type of coffee bean, but it’s brewing method. Any bean can be used to make it, though roasters often blend or dark-roast beans to hindle the high-pressure extraction. A a single 1-ounce shot of espresso has around 63 miligrams of caffeine. While it is stronger per ounce than drip coffee, a standard 8-ounche cup of drip coffee usually contains 80 to 120 miligrams of caffeine in total.
The origins of the commonly known beverage came from Angelo Moriondo who built the first espresso machine prototype in 1884 which was 142 years ago, and Luigi Bezzera was the one who improved it for individual servings in 1901. The word “expresso” came from Italy and translates into the word “pressed out” or “made just for you”. Further on we also have Achille Gaggia who invented the spring-piston lever machine in 1947, which made high pressure extraction and made the modern crema possible.