What are the 4M's of espresso? "4M" is something that I have been heard of as a requirement set for tasty espresso.

What are these four important quality factors that affect the flavor of final espresso cup?
4M is a term mainly used among Italians for espresso. It is a placeholder for four words that start with "M" in Italian that affects espresso preparation. Some information can be found here.

These M's are:


Miscela: The coffee-blend; it covers the selection and blending of the beans as well as proper roasting.
Macinazione: The grinder; proper grinding of the given blend and its usage when its still fresh.
Macchina: The espresso-machine; usage of the given grounds with a proper espresso-machine.
Mano: Skill of the barista; usage of all above with skill.