A hot, dry wind blew down Dry Creek Valley. Every other vehicle on the road towed a boat toward the lake, a better idea than tasting red wine, no doubt. It was the kind of day for which ice-cold beer was made. Somewhat replenished with deviled eggs and soda at the Dry Creek Store, we were ready for one more winery, so long as they were serving chilled whites.

Up the road apiece, a brand-new sign announced, "Biodynamic wines." Frisky goats and sheep were in evidence adjacent to a weedy vineyard. Sheep, as I have previously maintained in this column, are widely known to be wooly and cute, and make excellent poster critters for a biodynamic farm. We might as well take a look. Today is just as good as any other day, right?

Many wine drinkers acknowledge that wine tastes better or lesser on certain days; biodynamic practitioners say that their calendar can explain that. Unfortunately, it's more challenging than just following the waxing and waning of the moon. Astronomic alignments and planetary positions make a rigorous calendar, one sliced up into fruit days, root days, leaf and flower days. Might has well add plain old hot, dry days into the mix. Truett-Hurst (née Martin Family Vineyards) is a new partnership among several longtime wine folks. The wines are currently made offsite from purchased fruit, their biodynamically farmed estate planted with choice heritage Zinfandel and Primitivo clones. The airy and barnlike tasting room is clean and welcomingly cool, furnished with rough-hewn recycled materials and abounding with rustic decor and references to resident critters. There's a well-appointed patio from which to view said critters, and visitors may continue on past the gardens, to view the steelhead habitat down by the creek.

Uh-oh. The roster includes no whites, but the Zinfandel Rosé ($15) is a nicely balanced refresher with some aromas of rose-petal and strawberry. Our affable host had a quirky, deadpan sense of humor and bears a passing resemblance to a midcareer Steve Martin. Since I didn't get his name, I'll call him Steve.

The Zinfandels were brambly, spicy and woodsy, with the 2006 Three Vineyards, Dry Creek Zinfandel ($25) the most subtle of strawberry fruit, spiced with white pepper and coriander. The only currently available biodynamic wine, 2007 Dark Horse (a Mourvedre, Grenache, Petite Sirah and Syrah blend, $40) was perhaps the most sumptuous of the offerings, showing red blackberry fruit, framboise, over a leathery, deep palate. And this wasn't even a "fruit day."

Steve says that the 2006 "Burning Man" Petite Sirah ($33) isn't about fire, drugs and getting naked; it's about campfires and wine, basically. That's good enough for me, and it's a dead-on Petite for fans of the varietal, with patent leather and purple marker over smoke, berries and tar, finishing dry. I'd want to cellar it for two or three years, or at least keep it in a deep, cool pantry out of heat like this and then open it when the stars are just right.

Truett-Hurst, 5610 Dry Creek Road, Healdsburg. Tasting, 11am–5pm daily, no fee. 707.433.9545.

Send a letter to the editor about this story.