Sweetness is one of four basic sapid (in the mouth) tastes: Sour, Sweet, Salty, Bitter (and possibly a 5th called Umami which indicates savory flavors). In coffee, sweetness is a highly desirable quality, and the green bean has many sugars and polysaccharides. However, the main sugar, sucrose, is largely destroyed by roasting, with only 2.9% remaining at a light roast, and 0% at a darker roast. When caramelized sugars have aromatic sweetness, but not sapid sweetness on the palate. Hence, over-roasting is to be avoided to preserve some sweetness.