Sight
The perfect espresso can be recognized at first sight
The first thing you do with an espresso is look at it, and there are many things a trained eye can recognize at first sight.
The white china frame allows you to observe the surface of the crema more clearly. The surface of a perfect espresso crema has a subtle texture lined with light tiger stripes, is between 3 to 4 millimeters thick, and its color ranges from hazelnut to darker shades. This color is a real litmus test for quality. A darker shade of brown, with a white button or a dark hole in the middle indicates that the extraction time was too long, the grind was too fine or the temperature or water pressure were too high. Espresso with a sparse, light-colored crema indicates it was extracted for too short a time, that the water temperature or pressure were too low or the grind was too coarse.