Coffee experts talk about four basic components that blend to create the perfect cup; aroma, body, acidity and flavor. The aroma is familiar and obvious enough that fragrance that often promises more than the taste delivers. Body refers to the feel or"weight"of the coffee in the mouth, how it rolls around the tongue and fills the throat on the way down. Acidity refers to a sparkle, brightness, a tang that adds zest to the cup. Finally, flavor is the evanescent, subtle taste that explodes in the mouth, and then lingers as a gustatory memory. Coffee is such a delicate fruit that almost any difference in where and how it's grown, picked, graded, sorted, processed, packaged, and shipped even its botanical DNA seems to make a marked difference in how it tastes in your cup. Understanding these differences is essential for learning how to choose the best beans, whether already roasted or those you plan to roast yourself.