Since whole clusters are used during fermentation, the grapes are harvested late to avoid unripe stems. Whole-clusters are put into the vats, and the weight of the grapes naturally crushes the fruit at the bottom of the tank, resulting in a traditional semi-carbonic maceration.  Fermentation starts naturally from the ambient yeasts on the berries. The vats are covered to keep some CO2, but not sealed. Fermentation goes slowly at about 3 weeks total, and then the wines are aged in cement vats and kept on the lees. The lees have a reductive quality and help to preserve the wine naturally. No sulfites are added to this wine at any point during the fermentation, aging or bottling process.