An espresso's aromatic fragrance may be reminiscent of flowers, fruit or chocolate.
The crema of a perfect espresso should never be frothy, too light or too dark, nor should it disappear quickly.
An espresso's body — meaning its structure and thickness — results from the concentration of dissolved substances in the liquid. The density, oiliness and viscosity of coffee can be distinguished and measured separately from the intensity of its flavors and aroma.
The perfect espresso may have higher or lower levels of bitterness, acidity, saltiness and sweetness, depending on which of these tastes is most prominent in the blend.