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. Natural processing is when ripe cherries are dried with the cherry still attached. Leaving the pulp on during drying results in a sweet, fruity coffee. But there is greater risk of over-fermentation and mold developing because of the high level of moisture involved.