What exactly is a Prune? Well basically they are fully ripened plums which have been dried to remove most of the water. But not all plums are suitable to be dried into prunes. The most common variety of plum used for prunes is d'Agen. At maturity, they have a deep purple skin and they have a higher acid content and more sugar which makes it possible for the fruits to be dried with their stones intact without fermenting. Prune by Demeter Fragrance Library captures the intense and concentrated sweetness and fruit of the dried plums, in their purest form.