by Larry Brooks, Consulting Winemaker - Enologix

“Trefethen is uniquely blessed from a viticultural perspective. The family owns all their vineyards enabling them to be one of a few truly estate grown wineries in the Napa Valley. The Oak Knoll District where they are located is one of the rare places in the Napa Valley that is warm enough to ripen Cabernet Sauvignon and Merlot without being too warm for Chardonnay and Pinot Noir.

In general the region is cool, but soil variation within their vineyards produces sites where the soil warms more quickly in the spring. These areas begin growing earlier and result in a greater capacity to ripen, which Cabernet needs. Combining these warmest sites with limited crop yield allows Cabernet and Merlot to achieve full maturity each vintage.

The marine influence which is strong in Oak Knoll gives cooler than average temperatures and higher humidity than most of the rest of Napa Valley. These two climatic characteristics are essential for preserving aromatics in the grapes and wine. Aroma is vitally important in white wine. While the cool air severely limits the Cabernet crop size, it more than repays it with increased complexity of bouquet in the final bottling. What is critical for the quality of Chardonnay becomes a grace note for the Cabernet and Merlot.”