The Castello Banfi estate is a constellation of single vineyards.
The slopes offer great possibilities for site selection by variety; Chardonnay and Pinot Grigio, for example, are grown at between 750 and 1,380 feet above sea level, where the nights are cool and the ripening season long. Chardonnay is the most widely planted white grape while Brunello, the local small-berried version of Sangiovese, is the principal red variety, covering approximately 365 acres.

When planting most of the international varietals, Castello Banfi's winemakers relied on documented studies, professional advice, and their own experience to select the proper vine clones for the diverse soils and sun exposures on the estate. Yet they found no scientific standards or documented results for the Sangiovese, despite a centuries-long history of that vine in the area. On their own, they identified over 100 distinct clones of Sangiovese Brunello. They first narrowed the selection down to 60, which they planted in experimental vineyards on the Castello Banfi estate. Through subsequent field study and microvinification, the selection was further narrowed to a final six clones, based on their individual contributions to the final blend, including color, structure, tannin, body, and bouquet. Not only did Castello Banfi plant new vineyards accordingly, but shared the results with neighboring producers. The residual of this practice is increasing quality standards throughout the region.