Fresh from the Old Vine Conference 2025, Jason Millar discovers how California’s old vine renaissance is reshaping the state’s red wine story, with Zinfandel at its core.

When considering Californian wine, the first thoughts that come to mind might be million-dollar Napa vineyards, the Judgement of Paris and verticals of Screaming Eagle. But as the most recent Old Vine Conference demonstrated, there is another California – one rooted in old vines, field blends and heritage vineyards planted by immigrants.

Zinfandel dominates these plantings and has been driving the conversation about old vines. The variety was California’s most-planted grape in the 19th century, a position it held until the 1970s. For many decades it was considered and treated as a uniquely Californian variety, but following research led by Mike Grgich and Carole Meredith, Zinfandel was identified as Croatia’s Tribidrag and Puglia’s Primitivo.

By contrast, before the Judgement of Paris, Cabernet Sauvignon accounted for only a small fraction of the vineyard area in Napa. Today, those numbers have shifted: the variety represents two-thirds of plantings and nearly 80% of value.

Market forces

Across California, unpicked fruit from the 2025 harvest reflects another year of oversupply and cooling demand, shaking confidence in a wine industry long insulated by a strong economy and robust direct-to-consumer sales.

Prime Cabernet fruit is being left on the vine in expensive Napa districts such as Howell Mountain, giving many food for thought about its future. The downturn presents an opportunity for more accessibly priced Zinfandel, but old vine vineyards remain misunderstood and financially precarious.

It’s not just Cabernet. “Great old Zinfandel vines are being torn out in the Russian River area because growers can get so much more money for Pinot Noir,” says Paul Draper, chairman emeritus of Ridge Vineyards and an early champion of old vine Zinfandel. Today, only about 180ha of Zinfandel remain in Russian River.

Urban development also poses a challenge. “We’re in Napa Valley, but we don’t produce Cabernet and we’re happy to say that,” says Bob Biale of Robert Biale Vineyards. “We want to give a voice to these beautiful old vineyards still in the ground.” His Zinfandel sits on land valued at around $10m for development. The wines sell out, but Bob Biale hasn’t.

Old vine ambassador

Joel Peterson, founder of Once & Future, previously the driving force behind Zinfandel powerhouse Ravenswood, argues that Zinfandel is the ultimate ambassador for the state and the country. “Old Zinfandel vines have been at the core of Californian wine’s evolution,” he points out. “It’s a true American wine.”

Ironically, it was White Zinfandel that saved many old vineyards from destruction during the Cabernet boom, but it was a Faustian pact that exhausted the vines and tarnished the variety’s reputation. Peterson bought Bedrock Vineyard in 2002 from ‘nozzleheads’ (his term for industrial growers addicted to spraying) who had used it for White Zin. Two decades later under his son, Morgan Twain Peterson MW, it has become California’s first certified old vine regenerative vineyard, with vines dating to 1888.

Tegan Passalacqua, winemaker for Turley and his own label, Sandlands, has also been a devoted advocate for old vine Zinfandel. “I bought the Kirschenmann vineyard before I bought a house,” he says of the Lodi site planted in 1915. “Old vines are the best proof of what works for our soils and climate. They were planted in the most suitable sites at a time when they had to survive without the chemistry set of modern viticulture.”

Appreciating the ‘mixed blacks’

But there’s a catch. “A pure Zinfandel vineyard takes a long time to make good wine,” says David Gates, senior VP of vineyard operations at Ridge Winery. Gates’s experience is that Zinfandel performs best with other red varieties – the so-called mixed blacks. “If you co plant and co-ferment it with other varieties, it makes a far better wine,” he explains.

Ridge’s Geyserville is a Zinfandel blend with Carignan as the second variety, while its Lytton Springs features Petite Sirah as the second grape. At the Petersons’ Bedrock vineyard, Syrah, Mourvèdre (Mataro), Petite Sirah, País (Mission), Alicante Bouschet and Carignan are all present. “Carignan is an incredible ballast to Zinfandel,” remarks Twain Peterson.

In fact, old vine Carignan, with its freshness and modest alcohol, is one of California’s most contemporary reds. Ridge, Sandlands and Bedrock all make outstanding examples with it as the lead variety from old vine fruit, sometimes with Zinfandel in a supporting role.

Mourvèdre (Mataro) and Cinsault also deliver world-class wines, coping far better with California’s dry summers than Pinot Noir. Old vine Mourvèdre has been the basis of an outstanding Cline Cellars cuvée since the 1990s. Passalacqua, who champions old vine Cinsault under his Sandlands label, notes that it also makes appealing young vine wines, which could encourage new plantings.

Embracing old vine Cabernet

If Zinfandel has made the case for keeping old vines in the ground, it still struggles on the commercial side. “The best Zinfandel comes with a ceiling of around $75,” says Twain Peterson – far below the sums fetched by Cabernet or Pinot Noir, leaving it vulnerable. But Peterson believes the old vine conversation is now starting to reach growers of these varieties too.

Blair Guthrie, winemaker at Stewart Cellars in Sonoma, works with one of the few old vine Cabernet Sauvignon parcels in the state. “Cabernet dips at around 30 years – that’s when most people rip it out,” he says. “But with the right farming it maintains its yields and gains quality.”

Cabernet rarely makes the 35-year-old vine threshold, usually due to virus or yield concerns, yet some of California’s most collectible Cabernet – Scarecrow, MacDonald and Ridge’s own Monte Bello – come from old vines.

The prospects for ancient vineyards are now looking brighter. As Bruce Fry, the fifth generation of the Mohr-Fry family to grow fruit in Lodi, says, “Twenty years ago, we were ready to take these old vines out. But all of a sudden there was an interest.” That interest, driven by heritage, character and quality, seems to be growing. The argument isn’t won yet, but mindsets are changing thanks to initiatives like the Old Vine Conference. In 2025, there is increasing agreement that old vines are not just historical relics, but a valuable part of California’s future.