What is a Peaberry Coffee? Peaberry coffee is considered a natural mutation of the coffee bean inside its coffee cherry. Peaberry beans are a single, oval-shaped seed that is found in about 5% of coffee cherries. The peaberry coffee beans are smaller, denser, and rounder than regular flat coffee beans, and they don’t have the flat side. Although you may hear that peaberry coffee beans are found in certain geographical locations, the truth is, peaberry coffee beans are found in all regions, so the distinction is solely on anatomy.