Which type of espresso shot is characterized by a shorter extraction time and a sweeter flavor?

The type of espresso shot characterized by a shorter extraction time and a sweeter flavor is a ristretto. This espresso is made using the same amount of coffee grounds as a standard shot but with less water, resulting in a brew that is concentrated and has a richer, sweeter taste. Because the extraction time is shorter, the bitter compounds have less opportunity to dissolve into the shot, which allows the naturally occurring sugars in the coffee to shine through, contributing to that sweetness.

A solo shot refers to a single espresso shot, which has a standard extraction time and flavor profile. A doppio is a double shot of espresso, typically using more coffee and water, making it stronger and bolder than a solo shot. A lungo involves a longer extraction time and more water, which can lead to a more diluted shot with a tendency toward bitterness rather than the sweetness of a ristretto. Each of these other options has distinct characteristics that are different from the ristretto's shorter extraction and sweeter flavor profile.