Tucked away in the Goldridge and Altamont soils along Vine Hill Road in Sebastopol, Dehlinger Winery has been quietly questing for quality since 1974, when a former pre-med student and trained enologist named Tom Dehlinger, with job experience at Beringer, Hanzell and Dry Creek Vineyard, bought an old apple orchard in the Russian River Valley and made his first set of wines, starting with chardonnay, zinfandel and cabernet sauvignon.

That was with purchased fruit. The goal was always to be an estate winery.

"This property had a reputation for having the earliest apples in Sebastopol, an indicator of good land," Dehlinger said. "I planted red grapes in red soil, the Altamont, which is more or less in the hillsides, and white grapes in white soil."

He and his brother soon built the now-iconic Octagon House at the top of a hill overlooking the newly planted vineyard: 14 acres of chardonnay, pinot noir, cabernet sauvignon and riesling, the latter long since gone.

"I had no conception that wine would become what is has become today," Dehlinger recalled. "My biggest ambition was to make good wine, not to make world-class wine. I didn't think there was such a thing at the time."

He added that there were only 35 wineries in Sonoma County when he applied to get his winery bond.

"Our idea of a great winery was Pedroncelli," he said. "They made good, solid wine at fair prices. We wanted to be like them."

Open sparingly to the public now, Dehlinger ran an active tasting room from 1980 through 1996, hosting as many as 15,000 people a year. But it was hard to balance the hospitality end of the business with the demanding vineyard and cellar work that had to be done, mostly by Tom.

"We closed and I gambled on being able to sell our wine through newsletter offerings," he said. "We've sold about 80-percent direct since then."

His wife, Carole, added, "Our biggest champions were our customers. Many have been on the list 20 years."

Today, pinot noir makes up exactly half of Dehlinger's 44 acres of plantings, followed by 9 acres of Wente-clone chardonnay, 3 acres of syrah and, rarer yet, 5 acres of cabernet sauvignon. The winery makes about 6,000 cases in total each year (they've made as much as 11,000/year), highly sought after by devoted wine list members and longtime followers in the restaurant and retail trade.

"No winery has done better with pinot, and, frankly, none really comes close," said Charlie Olken, publisher of the Connoisseurs' Guide to California Wine. "Dehlinger set the pace for pinot before the grape became so very fashionable, and now, with far more competition, Dehlinger remains at the top of its game. It is a singular effort borne of one man's continuing vision, and it is that vision that keeps Dehlinger at the top of the list of great pinot noir producers."

Vineyard plantings date back to 1975, 1982 and 1989, and most of the pinot noir vines were either Swan or Pommard clones. It wasn't until 2011 that Dehlinger undertook its first replanting, even adding the Calera clone to its pinot plantings, a process that's ongoing, mirroring the family's never-ending quest to make better wine.

"Over time, we've gone to thinning the grapes where the yield now is half what it used to be per acre," Dehlinger explained. "We have a really different conception of the kind of wine we want to make. It's evolved over time. We're constantly trying to improve."

Praised over the years for its undeniable consistency and quality, Dehlinger wines can be as elusive as the man himself, a soft-spoken figure.

Carole has been there since 1976. She's a gifted gardener with an acre-plus patch of estate-grown vegetables and has helped run the business alongside her husband for decades.

But it's two of the couple's daughters (there are four children in total, all grown) who hold the key to the future of this artisan family winery: daughter Carmen, who has taken on sales and marketing from her mom; and Eva, assistant winemaker to her 67-year-old dad, currently on sabbatical studying viticulture at the University of Dijon in France.

"We have a lot to celebrate. My parents were pioneering winemakers in the Russian River Valley. They've built a beautiful ranch and an incredibly loyal following," Eva said. "But there is still so much to do and explore. We all constantly ask questions related to increasing the quality of our wine."

She adds that the long-term goal is to re-enforce Dehlinger's reputation as a benchmark producer in the Russian River Valley, a region with dozens and dozens more brands and wines than when the winery was started. Its uniqueness lies in the fact that it's a fairly large estate and remains family-owned and operated.

"I see honoring our vineyard site as the central focus as we continue forward," Eva said. "Winemaking questions take generations to answer. It is a rare honor in California to make wines both from vines that you planted as well as grapes that your parents planted."

She offers as anecdote the process of replanting older vineyard blocks that they've been undergoing, detailing how her father continues to put a huge emphasis on establishing quality for the long term over any short-term gains. That means planting deep-rooted vines that can thrive with low-water input and maintaining a full-time, seven-person vineyard crew and vineyard manager.

"My parents think actively about our supporters and the importance of delivering something worthy to their table," Eva added. "The ultimate result has been a personal and unique product and I think it's fair to say that people take note of this approach."

Virginie Boone is a freelance wine writer based in Sonoma County. She can be reached at virginieboone@yahoo.com and followed on Twitter @vboone.