Vineyard work at Aalto is entirely manual, with the primary goal of maintaining low yields. Harvesting is manual and the grapes are transported to the cellar in small crates where they are sorted, chilled, destemmed, and sorted again before crushing. Fermentations are conducted, by parcel, in stainless steel, cement, or oak vats. Maceration is gentle with regular pump-overs ensuring a good extraction of fruit without harsh or bitter tannins. Once the fermentation is complete, the wines are racked, by gravity, into French and American oak barrels located in a cool, subterranean cellar. In recent vintages, Mariano has reduced the amount of new oak he uses in the aging of his wines and the time they spend in barrel – small, incremental steps to add more freshness and purity in his wines.
The primary wine, known simply as Aalto Ribera del Duero comes from vines ranging in age from 40–80 years old supplemented with younger vine fruit that is about 15 years old. It is aged in for 18 months in French (85%) and American (15%) oak with half of the barrels new. It is a voluminous Ribera del Duero showing Mariano’s deft hand at capturing both the power and grace of a variety, Tinto Fino, that tends towards rusticity in the hot climate of this region.