Hi, thank you for your comment 🙂 Crema is the icon that distinguishes italian espresso from other coffee extractions. Is the foam on the top of the espresso cup, its thickness must be about 3 mm, equal to 10% of volume (25-30ml). You can evaluate the quality of coffee used for the espresso by checking the crema: many tips play important roles like the color (noance and intensity), the consistency (compactness and quality) and the persistence. Crema is also very important for the espresso tasting: it acts as a lid that preserve a lot of volatile aromas until tasting. So before tasting a good espresso remember to breacking the crema as well you can do with the crust in coffee cupping, in this way you will enjoy the cup with a multi sensory tasting 🙂 Have you ever tried it?