The Machine
Because the espresso machine controls the temperature and pressure of the water as it passes through the coffee, it is crucial that it is clean and in good working order.
The Blend
A blend is any combination of "single-origin" coffees. Because few single-origin coffees provide all the flavors and aromas necessary for a good espresso, roasters blend several coffees together to achieve the taste they desire.
The Grinder/Doser
The coffee grinder/doser crushes the beans into small particles for brewing. Although espresso is always finely ground, there is no "ideal" particle size; the barista must decide how coarse to make the ground in order to achieve the flavor she desires.
The Hand
The skill of the operator is of great importance in espresso making - even with today's technically advanced machines.
