Crema

Crema is the dense, hazelnut-colored foam that naturally forms on top of a properly brewed espresso shot. It is created during high-pressure extraction (the process where water washes flavors out of the coffee grounds), as trapped carbon dioxide gas emulsifies with the natural coffee oils. While it looks visually stunning and is the signature mark of a fresh espresso, the crema on its own actually tastes quite bitter and powdery. Stirring your cup before drinking blends this top layer back into the liquid, unlocking a much more balanced sensory profile (the full range of flavors and aromas). The appearance of crema can immediately reveal a barista's technical mistakes or tell you if the coffee beans have spent too much time on a shelf losing their freshness.