Dolce, the botrytised, late harvest dessert wine, is produced from its own 20-acre Napa Valley vineyard. The land is located in an area known as Coombsville, east of the city of Napa, and is situated at the base of the Vaca Mountains, which define the eastern border of the valley.
In the vineyard, the crucial factors of soil, microclimate and vines combine to create suitable conditions for the development of botrytis cinerea, or noble rot, the mold that attacks the grapes and enables the production of Dolce. The volcanic soil is loose and well drained and the west-facing vineyard is protected from the prevailing winds so that the damp, morning fog – a very important component in the development of botrytis – hangs longer among the vines, often until midday. The vines are trained on trellis systems that protect the fruit, while allowing the botrytis to prosper.
Dolce is produced from a combination of Semillon and Sauvignon Blanc grapes. The vineyard is planted on several clones of these varietals, in the interest of finding the ideal pairing of clone and microclimate.
The production of Dolce depends each year on the arrival of botrytis in the vineyard. Once the mold begins to develop on the berries, its mission to concentrate the sugars and flavors in order to produce exceptional wine may only be accomplished when specific weather conditions exist. A combination of high humidity followed by drying encourages the mold to grow and spread, but its coverage on the grapes is not uniform; individual berries become botrytised at different rates. Harvest, therefore, is a slow process, requiring handpicking of individual grapes, partial clusters or whole clusters. The harvest takes place during several passes through the vineyard, stretched out over about a six-week period and often extending into late November.
The size of each harvest depends largely on how much botrytis proliferates in the vineyard. Grapes are lost by developing the wrong molds that create a sour flavor in the fruit, and to pests such as yellow jackets, which feed on the sweet juices contained in the grapes. While the vineyard produces four-to-five tons of grapes per acre, the final yield, after botrytis infection and picking all of the useable grapes, calculates to about one ton per acre.