This is de Bartoli's basic passito from the island of Pantelleria, issuing from August-harvested Zibibbo sun-dried on straw mats for two weeks. Of course, being de Bartoli, nothing about this elixir is really "basic".
From Marco de Bartoli: "Each year the harvest reveals different sensations and potentials. In Pantelleria those are amplified. During the harvest, Marco De Bartoli often used to say that the essential ingredient for making his own passito was ‘the sun of August’, the month during which Zibibbo grapes are laid down for sun-drying. That is why Sole d’Agosto (the Sun of August) is the name given to the younger and lighter passito produced every year in Bukkuram’s vineyard." Organic.