The portion of the municipality of Castelnuovo Berardenga included in the area of Chianti Classico wine production is often described as having a shape similar to that of a butterfly’s wings. The left wing, like we will explain later, is known as UGA Vagliagli, while the wing right is called Castelnuovo Berardenga. This area has a strong historical and geographical connection with the village of San Gusmè, which marks a relevant boundary also in terms of viticulture, as there there are a few vineyards north of the town centre. Interestingly, different geological formations or units maps follow one another in a fairly defined altimetric order, more precisely than is typical in the Chianti region Classic. To the north, in the higher areas, we initially find the Macigno and then the Alberese, often interspersed between them. Some small areas follow attributable to the Sillano Formation, followed by a vast area of Sands (known locally as “Sienese tuff”) and concretions marine. In the extreme southern part there are clays and marine silts, but their importance in wine production is marginal compared to other formations.
Considering the distribution of geological formations and vineyards, we note that from San Felice to Arceno, the altitudes remain at average between 350 and 450 meters above sea level. From Bossi to Rancia, instead, the altitude fluctuates around 300 meters, and then reaches lower altitudes between 200 and 250 meters above sea level from San Piero by boat to Monte Giachi.
The UGA of Castelnuovo Berardenga has a total area of 5370 hectares, of which 14.2% is used for vineyards (760 hectares in total) and 9.3% is used for olive groves (9.3% of the total).