Preparing an espresso requires a lot of precision and the expertise of a good barista. The coffee is always ground just before extraction.

The recipe for the perfect espresso (30 ml) is as follows:

• Tamper pressure: 20 kg
• Coffee quantity: 8–10 g
• Water pressure: 9 bar
• Water temperature: 92°C (between 88 and 96°C)
• Flow time: 22–30 seconds (longer if pre-infusion)
• Grounds after extraction: Almost dry and solid puck, few residues in the portafilter.

If your espresso flows in more than 30 seconds, your grind is too fine; loosen your burrs and make it coarser. You can also try to use a little less coffee. If, on the other hand, your coffee flows in less than 22 seconds, make it finer and/or slightly increase the amount of coffee.

The "crema": A good espresso should have a beautiful, uniform, light, untigered, and fairly thick layer of crema that doesn't disappear before 4 minutes.

The cup should always be preheated, and its walls should be thick enough to ensure good thermal inertia.