Peaberry

The normal development of the coffee cherry creates two seeds, which grow with their flat sides facing each other. Infrequently, one seed fails to thrive and a single, round bean fills the available space. Often sorted out and sold separately, these single beans are known as "peaberries" and are technically mutant growths. Some in the coffee trade argue that peaberries have a richer, more concentrated flavor than normal beans, but others claim that they cannot discern a difference in a blind cupping. Today, the most famous peaberry is probably Tanzanian, where the plants seem more prone to producing peaberries than anywhere else. But you can often find peaberry-only versions of Kona, Kenyan AA, Java, and other types of "famous name" coffees.