100% Grillo. All De Bartoli's marsala wines are pure Grillo, a rarity--as is its being organically farmed, estate-only, hand-harvested fruit. The bunches are gently pressed and the must fermented spontaneously with natural yeasts in wooden vats. The wine is first aged for a year in conical wooden vats called tini. From here, wine destined to become a Superiore is drawn off and fortified with a mistella, a combination of fresh Grillo must and distilled Grillo spirit, again all from De Bartoli fruit (another rarity). The fortified wine goes into a solera system of barrels of varying sizes and ages; there is no flor like in Jerez, and the barrels in this fractional blending system are never fully topped, so the aging of the wine in the system is oxidative. For their vintage-labeled Superiore Riservas, the wine is drawn off to be further aged, untopped, in individual barrels; that year of its going into barrel becomes the vintage date on the bottle. The Marsala DOC requires a minimum aging of only 4 years for Superiore Riserva; De Bartoli’s versions are from 10-20  years before bottling. They are semi-secco or "semi-dry" due to the original fortification with mistella (the must portion of it is naturally full of sugar). Residual sugar is usually in the 50-60-grams/liter range. 

Note: the “Oro” in the name of the wine simply indicates that the grapes in the wine are all authorized white varieties (again, De Bartoli uses none except Grillo).