The simple definition of Espresso – coffee liquid on which you pour steamed milk to produce a cappuccino or latte. If you just pour it over hot water, you get an Americano.
Only if making it were that simple. There is science behind espresso.
This method of extraction differs from others as hot water is under pressure and percolates rapidly through the grounds to extract the oils and other aromatic compounds from the coffee. It is a concentrated beverage, much more than a filter coffee. However, it doesn’t necessarily contain more caffeine than filter coffee.
The light colour foam that you see on top of espresso is called crema. Crema contains coffee oil and Carbon Dioxide.
A quick history lesson. Contrary to popular belief, espresso invented in 1820 had its roots in France, before being popularized and refined by the Italians. At the Turin exhibition in 1884, the Italian entrepreneur Angelo Moriondo exhibited his “steam machinery for the economic and instantaneous confection of coffee beverage” for which he was awarded the Bronze Medal. At the time, it wasn’t yet known as the espresso machine.
Espresso is drunk quickly, within 2 minutes of brewing it. That is why it is called an espresso “shot”. To properly appreciate an espresso, you need to taste it, savour it as you would do with wine.
A Good espresso is produced when it is brewed under high pressure (9 BAR) at 90-95 degree Celsius water temperature in 20-30 seconds at a brew ratio close to 1:2.
Good espresso machines are usually expensive. However, to get something closer to an espresso at home, one can brew coffee in a Moka Pot or Aeropress. Both methods give you a decent body and strength closer to that of espresso, albiet not as concentrated.
To brew an espresso, people usually prefer blends – a combination of coffees of different origins. For espresso, blends are safer to brew as this maximises the chance of obtaining a consistent coffee that is more balanced. In the right dose, blend combines qualities of various coffees and gives you a smooth, consistent and balanced cup.
However, some coffee enthusiasts prefer single origin espressos as they enjoy those nuanced characteristics unique to each coffee. Gowri from Shevaroy Hills, Tamil Nadu roasted by Quick Brown Fox and M.S. Estate from Chikmagalur roasted by Half Light Roasters are some great examples of single origin coffees roasted for espresso.