The ocean dominates Anderson Valley's climate; afternoon breezes waft in from the coast and almost nightly, fog blankets the valley, often so thick that the vines are dripping wet in the morning. Various rots can affect the grapes all season long, but botrytis, the sole beneficial rot, can only be noble if it occurs near the end of the season under certain weather conditions. It takes rot about 72 hours of wet weather before it sporulates and then rapidly spreads. To avoid ugly rots, our task for most of the summer is to get the grapes dry before the next evening's fog bank rolls in, since drying out clusters is the most effective method of rot control.
These two charts show why Anderson Valley has ideal weather for late harvest wines. Philo's nighttime temperatures are ocean influenced and very chilly enabling ripening grapes to retain most of their high natural acidity, critical in sweet wines to counterpoise the residual sugars and provide a clean, tangy finish.
Chart 2 demonstrates the see-saw of high nighttime humidity caused by fog, creating perfect conditions for rot. After most of the berries are affected with botrytis, dry weather is needed to dehydrate the berries, thus concentrating the juice into luscious nectar.
Harvesting in a cool and wet October. The day preceding harvest, we removed all the leaves around the fruit so workers could evaluate the condition of each cluster before picking. In 2011, Navarro's vineyard crew was split into two teams; the first team harvested all the clusters with rot, the second team picked the remaining sound fruit.
Afternoon breezes are perfect for drying the grapes, provided the canopy provides sufficient air movement around the clusters. Good trellis design, combined with training and shoot positioning, are mandatory for successful viticulture in Anderson Valley. After two October storms in 2011, botrytis was rampant in our Riesling vineyards; the rain stopped, the days were cool and the nighttime temperatures were in the forties. In late October, dehydrated clusters and berries started falling on the ground, so we finally decided to harvest. This wine is a gift of those storms, the rot they caused and then, the dry weather that followed. Riesling's stone-fruit flavors are layered with botrytis's signature of honey, apricot and pineapple. Gold Medal winner. Best of Class, and at the Critic's Challenge International Wine Competition it was declared Wine of the Year, the top wine from 1365 entries from thirteen countries!