Coffee is at its freshest immediately after it is ground. After grinding, the volatile oils that were previously protected inside the coffee bean are exposed to the air, which starts the oxidisation process and stales the coffee. For this reason it is important to tamp and extract coffee as quickly as possible.
The experience of coffee comes to us through several different senses. The most important of these is the sense of smell, which allows us to perceive the aromas of the coffee.
When you experience these aromas while drinking coffee, they are experienced as flavours. These perceptions are different from those which come to you solely through the sense of taste – sweet, sour, salty and bitter.
After the senses of smell and taste, the next most important sense in experiencing coffee is that of touch.
You touch the coffee with your lips, tongue and palate when you sip it. It can feel thick or thin, watery or syrupy (body).
Finally, some attention is paid to how the coffee finishes – what it tastes like after you have swallowed it.
Savouring the aftertaste of a coffee is something that can stay with you long after you have consumed it.
A typical single shot is:
7-9 grams of coffee + water = 1 1/8 oz of espresso, including crema. Using a portafilter equipped with a single basket makes single shots.
A typical double shot is:
14-16 grams of coffee + water = 2 1/4 oz of espresso, including crema. Double shots are made using a portafilter equipped with the deeper double basket.
Extraction time = the amount of time the coffee is in contact with water under pressure from the espresso machine.
There are three things which affect extraction time:
• Dose – how much coffee you put into the portafilter.
• Tamp – how hard you pack the coffee in the portafilter.
• Grind – how fine or coarse the coffee is ground.
Discover the Art of Espresso, © Justin Metcalf 2013 (World Barista Judge)