The practice of Italian espresso

The coffee beans that make espresso are usually Arabica beans. It doesn't matter whether you use individual beans to brew Espresso. There is a lot of freedom to choose. Some coffee merchants even sell coffee beans used to make espresso that are a mixture of several Arabica beans.

The coffee powder for making espresso should not be ground too fine, which will cause the coffee to be over-extracted and make the coffee taste bitter. On the contrary, the coffee will not be ground too thick, so the extracted coffee will taste too light.

The most important sign of a good espresso is that it has a light camel-colored emulsion (Crema), which is a mixture of fat, water and air in the coffee during the extraction process. The emulsion should be uniform in color, about 3 cm to 5 cm thick, shake the coffee cup gently, and this layer of emulsion will stick to the wall like thick syrup. If the emulsion is dark brown or even black, the coffee is overextracted; if it is yellowish, the coffee has not been fully extracted.