Whether you take your espresso with a side of sparkling water, with a dollop of foam, or mixed in with warm milk, espresso is the corner-stone in the modern coffee shop. There are many aspects to making a good espresso. You can subscribe to a number of schools of thought about espresso, but there are fundamental building blocks in understanding this delicate coffee giant.
- Espresso is a grind, not a roast. The barista's challenge is finding the right grind setting to make their espresso. Any type of coffee can make good espresso, as long as the coffee beans are ground fine enough. Grind the beans too fine, though, and the water in the espresso machine will have a hard time getting through the espresso puck -- making your espresso bitter and over-extracted. On the flip side, if the beans aren't ground fine enough, the water shoots right through the puck -- making your espresso sour and under-extracted.
- Get your tamp on. Tamping is another art in it of itself for the barista. Tamping is the compacting of espresso grinds in the portafilter -- creating the espresso puck. By pressing the grounds together, the barista is eliminating the air between the grounds, making it easier for the hot water of the espresso machine to extract the delicious flavor of the beans in a concentrated way. 30lbs of pressure using a tamper is the standard starting place for an appropriate tamp.
- Time heals all wounds. Closely related with grind setting, time is an important indicator of how your espresso shot will taste. There is a time 'sweet spot' for every origin and roast ever created. A lighter roast might have a shorter sweet spot than a darker roast to enhance the fruity and sour flavors inherent in the coffee -- whereas the darker roast's potentially longer sweet spot may highlight the more bold and chocolate flavors that pair so well in your latte. Typically, espresso shots run anywhere from 20-40 seconds depending on the roast, origin, and water temperature. Extensive experimentation is crucial in discovering these sweet spots!
There are many, many aspects to creating good espresso that are hotly debated among the coffee elite, but at the end of the day, these three notions are apart of the espresso theory foundation.