Doppio in espresso is a double shot, extracted using a double coffee filter in the portafilter. This results in 60 ml of drink, double the amount of a single shot espresso. More commonly called a standard double, it is a standard in judging the espresso quality in barista competitions. Doppio is Italian, meaning `double`. A single shot of espres..... Found on http://en.wikipedia.org/wiki/Doppio