Rutherford, Calif. -- Coincident with its 30th anniversary July 4, Grgich Hills Estates has released its first biodynamically produced wine, a limited-production 2006 Sauvignon Blanc called Essence. Grgich Hills owns 366 acres, all certified organic and farmed biodynamically. Most of the vineyards are certified biodynamic by Demeter Association, and the winery expects the rest to be certified this year.

Co-founder and winemaker Miljenko "Mike" Grgich says, "We believe that we are the largest biodynamic grapegrower in the country." The grapes were grown primarily at Grgich Hills' cool American Canyon vineyards in southern Napa Valley, which limits vigor, producing fewer grapes with more intense flavor.

The year had a wet winter and spring, with slow, even ripening followed by a heat spikes in July and then an unusually cool fall that allowed the grapes to completely ripen without dehydrating. Grgich's nephew and vice president of vineyards and production, Ivo Jeramaz, says, "We experienced very little botrytis, we think because of our dry farming and biodynamic techniques. The vines remained healthy in the heat, providing fully ripe, flavorful grapes in September."

The grapes were hand-harvested at night Sept. 13-22 at 23.9º Brix into small bins, so they arrived at the winery cool and intact, preserving the flavors and acidity. The wine was fermented with naturally occurring yeasts in 900-gallon French oak casks that are temperature controlled for a slow fermentation to retain the grapes' aromas.

The best lots of the vintage were aged for seven months in large oak casks. This extra aging adds another layer of complexity, but the larger casks don't overwhelm the fruit flavors with oak. The wine has classic Sauvignon Blanc aromas of citrus blossom, lemongrass and juicy kiwi, balanced with a touch of minerality. It has an alcohol level of 14.3%, pH of 3.22 and total acidity of 6.9 g/l. Production was 374 cases and the wine has a suggested retail price of $40.

The wine was poured at a vertical tasting to celebrate the winery's 30th anniversary, attended by Robert, Tim and Margrit Mondavi. Grgich worked for Mondavi before founding his own winery, and Mondavi assisted him in getting started.

In the tasting, Grgich Hills Chardonnays dating back to 1986 remained vibrant, with the 1992 perhaps the best of the lot. Grgich attributes the ageability of the wines to traditional winemaking techniques, including picking when grapes are at the peak of ripeness but not overripe and avoiding malolactic fermentation. "Why remove malolactic acid, then replace it with purchased acid?" he asks.

Fads come and go, but the 84-year-old Grgich and his nephew still make wines as they once did, and the results speak for themselves. "We don't make wines for the critics," Grgich says. "Their tastes change. We make wine for ourselves."

The winery has changed with time, however, and now ferments whites in casks-some large and old-rather than stainless, and has recently started rotating the barrels rather than stirring the lees to avoid oxidation.

The reds also showed well, with the 1985 peaking, though the younger wines are a bit softer to start with.

During the discussion, Grgich and Jeramaz disclosed that the winery has 40 acres of Cabernet on AXR-1 rootstock planted in sand that is still producing. In another old vineyard, 80 to 90% of the vines were virused, judging by the color of the leaves. After converting to head pruning and biodynamic farming, including dry farming, Jeramaz says, "Now we only see about 10 to 15% with viruses," though production is only about 2 tons per acre. The winery's oldest vines are 110-year-old Zinfandel vines in Calistoga.