Espresso is the result of pressurized water flowing through finely ground coffee beans, resulting in a 23-27 second pour that looks like a flow of warm honey. The 1-ounce to 1.5-ounce shot should finish with a light-nutmeg colored "crema" on top. Some people test an espresso shot by counting the number of seconds it takes for a teaspoon of sugar to slip through the crema. At least two seconds should indicate a decent shot — three is better.
Espresso, often mispronounced "expresso," is the basis for several beverages in coffeehouses and cafes in the United States and around the world. This article explains the espresso menu at Starbucks, the company that undoubtedly sells more espresso shots than any other. For an illustrated guide to espresso drinks, click here. The person making those drinks is often called a barista.
Espresso has inspired a multitude of enthusiasts both within the blogosphere and in society, some of whom contend in barista competitions.