Updated: Sep 9, 2018
Before you start, make sure your espresso machine is up to temperature (about 92°c ) and your machine group head & portafilter is cleaned and pre-heated. You should also start with a pre-warmed cup.
Fresh Roasted Coffee Beans is essential to a quality cup, always grind coffee fresh every time you brew. Always use a burr grinder ( flat or conical ) to grind your coffee, pre-ground is not recommended, unless you use blade grinders.
Grind your coffee too fine and result will be a slow extraction resulting in an over-extracted shot, the taste can be bitter and burnt. Grind your coffee too coarse and the shot will extract fast resulting in an under-extracted shot, the shot will have a weak 'crema', lacking body, and taste weak and watery.
The dose is the amount of ground coffee used to make your espresso shot. A single shot is usually around 10 g, double around 19 g. There are baskets for each size. Double baskets are the most common. Always weigh your ground coffee to fill your filter basket up, gently flapping, quickly but slightly shake to level the coffee bed all the time. Experimentation is key.
Tamping is often neglected in espresso preparation, the espresso pellet must be hard and evenly tamped, the goal is to create a pellet of coffee through which the hot water from the espresso machine will penetrate evenly. It is important to prevent paths of least resistance in the coffee pellet and force the water to evenly permeate and extract the coffee. The key is to evenly distribute the coffee without pressing into the grounds or leaving any empty space on the sides of the basket.
In general, proper espresso extraction requires about 26 seconds to produce around 30 ml(single shot) or 60 ml(double shots).
Before you lock the portafilter, flush some water to stabilize the brewing temperature while also clearing any stray coffee from the group head. Lock the portafilter and immediately start brewing the coffee.
If the espresso extraction too fast, your grind is too coarse, if the espresso extraction too slow, your grind is too fine. Adjust grinder setting when necessary while keeping your dose and tamp consistent. Repeat the extraction process and keep adjusting the grind until you achieve the good extraction.
Once you have your grind, dose, and tamp dialed in correctly you should be able to produce consistently great espresso time after time.
*We are not suggesting that they are gospel. There is a way to do it better, find it. Once you have worked out how you like your coffee, you brew it your way. *