What is the explanation why some coffee cherries have peaberries and others do not? And is this phenomenon particularly common in some varieties compared to others?

Hi Anna!We are all familiar with how a coffee bean typically consists of two seeds, with their flat sides facing towards each other. However, there are certain times that these beans mutate and a peaberry is born.Its formation occurs when only one of the usually two ovules fails to pollinate. This means only one bean gets to live inside the cherry developing a small, rounded shape that's much denser than the regular beans.There is no way to identify a peaberry before it's removed from the cherry. In addition, they compose about 5% of the total coffees harvested. They're pretty common in Arabica and Robusta varietals, and in regions like Tanzania, Kenya, and Hawaii.