Brewing coffee as espresso is truly a labor of love. The addition of pressure to coffee preparation makes espresso extraction as maddeningly complex and ever-changing as it is delicious. The standard recipe and preparation procedure for our house espresso blend, One Black, is included below, as are links to online resources which might help you on your journey as a home barista.
What you need: Freshly roasted coffee, a kitchen scale (more measuring input and output weight), a timer, espresso grinder, and an espresso machine.
What you do: Grind out 18.5g of coffee into portafilter. The optimal grind setting for an espresso can vary widely, but in general, espresso coffee is ground very fine.
Use thumb and forefinger (or better yet, a distribution tool) to distribute the ground coffee evenly throughout the portafilter.
Tamp firmly and evenly with around 30lbs of pressure.
Purge grouphead on espresso machine, then lock in portafilter with tamped coffee. Start shot and timer.
Pull 37g of espresso in around 30 seconds. If your grind setting is correct, drops of espresso should hit the cup in around 3-5 seconds. The coffee will begin to flow evenly around 8-10 seconds and will turn blonde and lose viscosity around 30 seconds, at which point the shot must be stopped. Too short of a shot and your espresso will taste sour; too long of a shot and it will taste bitter.
Knock out spent espresso puck and purge grouphead again to clean out coffee residue. We recommend enjoying your shot with a small glass of sparkling water.