Why Drying Matters
In general, an unprocessed, ripe coffee bean contains around 45–55% moisture after picking.
The International Coffee Organization states that dried, processed green coffee beans should have a moisture content of 8–12.5% with the exception of “speciality coffees that traditionally have a high moisture content, e.g. Indian Monsooned coffees.”
The correct moisture content contributes to balanced acidities and a desirable aroma, which in turn help achieve good cupping scores. There’s some debate over the best moisture level, but 10–12% is generally accepted.

Coffee beans are dried in different ways depending on which processing method is used.