Time to extract a double shot espresso

It should take between 20 and 30 seconds to pull a double espresso shot. Shorter than that and you have either a problem with the grind being too course, or your tamping pressure being insufficient. If it takes longer than 30 seconds, the reverse applies: grind it too fine, or tamping too hard.

My step by step guide to making the perfect espresso shot.

Books on making espresso at Amazon.com.