Lungo (Italian for "long") is a coffee beverage made by using an espresso machine to make an Italian-style coffee – short black (single or double dose or shot) with much more water (generally twice as much), resulting in a stretched coffee, a lungo.
A normal serving of espresso takes from 18 to 30 seconds to pull, and
fills 25 to 60 millilitres, while a lungo may take up to a minute to
pull, and might fill 130 to 170 millilitres. Extraction time of the dose
is determined by the variety of coffee beans (usually a blend of Arabica and Robusta), their grind and the pressure of the machine. The optimum is obtained with 9–12 bars 130–150 ml.
In French it is called café allongé.