Markus Keller, Ph.D., a professor of viticulture at Washington State University, considers it part of his job to “burst bubbles and destroy myths,” he says. “To be upfront, there’s no scientific evidence that there’s any change in fruiting or fruit or wine composition as a vine becomes older.”
However, winemakers and wine connoisseurs often describe wines from old vines as Karin Wärnelius-Miller does: “There’s a depth, beauty, and sophistication you simply don’t see from a younger vineyard,” she says. Karin and Justin Wärnelius-Miller are second-generation winegrowers and the owners of Garden Creek Ranch Vineyards and Winery, a 100-acre hillside estate in Sonoma’s Alexander Valley. Their oldest estate vines are Cabernet Sauvignon, planted in 1969. Justin Wärnelius-Miller occasionally considers replanting or redeveloping older blocks, “But then, you go back to the blending table and find that’s your key ingredient—how do you replace that?”
Vine age doesn’t equate to grape quality, yet many winemakers feel that old vines offer flavor profiles they find distinct and irreplaceable. Here, scientists and winemakers discuss these contrasting views.
What are 'old vines?'
In 2024, the International Organization of Vine and Wine (OIV) adopted a formal definition of an old vine as a “single plant officially documented to be 35 years or older.” Otherwise, as Justin Wärnelius-Miller points out, the age at which a vine might be considered old has been subject to interpretation. “It often has to do with location, but I would say once you get past the 25- to 30-year mark, vines tend to be considered old,” he explains, adding that in some wine regions, vintners save the descriptor old for vines that are a century old.
For example, at San Leonardo in Trentino, Italy, the Guerreri Gonzaga family has produced Bordeaux-style wines for more than 300 years. Owner Anselmo Guerrieri Gonzaga observes gradual, incremental changes after year 25. “[This is when] vines have robust vascular systems, producing grapes of exceptional quality,” he says. “At 50 years, the vine achieves a remarkable equilibrium and ideal phenolic balance. Vines surviving beyond 100 years tend to produce fewer, larger grape bunches, reflecting their longevity and adaptation to the environment.”
The OIV’s new resolution also indicates that an old vineyard, in turn, must be composed of at least 85 percent of grapevines that meet the age criteria, buoying vineyard preservation efforts spearheaded by organizations like the Historic Vineyard Society (HVS) in California, the Old Vine Project in South Africa, and the Old Vine Conference, which runs the Old Vine Registry (a project begun in 2010 by Jancis Robinson, Tamlyn Currin, and others with an interest in safeguarding genetic and cultural viticultural history).
The HVS defines old vineyards as 50 years or older, with at least a third of the vines dating from their initial planting date, “to account for a couple of generations or more of people farming the vines,” says David Gates, the senior vice president of vineyard operations at Ridge Vineyards and an HVS board member. “This also takes into account the fact that you do lose vines over the years, as certain varieties are more susceptible to disease. Our start also corresponded with a big change in the way people were farming vineyards in California, moving away from head-trained, dry-farmed vines, as drip irrigation changed the way vineyards are planted. And, it’s also a working definition.”
Demystifying old vines
If we think of an older vine as we might an older human, there are helpful parallels. They’ve survived or avoided illness, proven resilient, and, as Guerrieri Gonzaga describes, adapted to thrive in their environment. For vines, vast root systems evolve to permeate layers of soil, tapping into moisture that can sustain them through dry growing seasons.
Part of the mythology of old vines is the presumption that, because old vines often yield less grape clusters, they create superior fruit from a smaller crop. According to the available research, this is where things become more complicated.
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