A Subtle Change Is Reshaping Winemaking In Napa Valley

Forbes

06-06-2025

Ehlers Estate in St. Helena, Napa Valley, California.
Alexander Rubin Photography
In a converted 19th-century stone barn in northern Napa Valley, a white wine is taking shape that upends more than it preserves. It is 87% sauvignon blanc, 13% sémillon, fermented in concrete, aged 14 months on lees and filtered for stability. Its structure is saline, its edges softened by time and skin contact.
It is labeled simply: Sylviane Estate Blanc.
'I almost never filter anything, including white wines,' says Adam Casto during a tasting session at Ehlers Estate in St. Helena, California. 'But I didn't want the first white wine release to have any risk of re-fermentation in the bottle. So I filtered this one.'
Casto joined Ehlers Estate as head winemaker in 2023 and this upcoming harvest will be his third with the winery. He was hired not to maintain the house style, but to rebuild it. His approach favors slow fermentation, concrete vessels and extended lees aging.
'The sémillon brings a salty, sea spray character, especially from the crystal lees aging,' he says. 'The concrete adds a little more body.'
The Sylviane is pressed after 24 hours of skin contact. It rests in a mix of neutral and new French oak, but not to impart flavor. 'That contact, combined with the concrete, helps turn the phenolic bitterness into a kind of structure,' Casto explains.
The result is not a white wine modeled after tradition but something else: an engineered response to site and conditions. 'This was very much inspired by white wines I tasted in Hungary in 2019,' he says. 'They paired with food in a way that reminded me of red wines—so structured, so food-friendly.'
This technical approach is now visible across the winery's small portfolio. The 2022 Portrait—a red blend of cabernet sauvignon, cabernet franc, merlot and petit verdot—was fermented in stainless steel and aged 21 months in French oak. So was the 2022 cabernet franc. But labeling now receives less attention than how each wine is built.
Casto has begun stripping varietal names from the front of bottles, starting with cabernet franc. 'It's like killing off a main character in a story,' he says. 'It opens up new possibilities.'
This philosophy now guides not only how the wines are made but how they are named and presented.
The new flagship red, for instance, was initially named 'La Lande,' in honor of the president of the Leducq Foundation, which owns the estate. That plan was abandoned when the team learned the name was under copyright in Spain. They have since planned to rename the wine 'Perdrix,' the French term for partridge. It is traditionally associated with wine through the term 'œil de perdrix,' used to describe the pale, coppery hue of certain rosés. The word also evokes Burgundian traditions, lending a classic tone to wine naming.
Perdrix blends cabernet franc and merlot, but its composition is only part of the point. The wine is designed to represent the entire estate, not a single variety. 'The wine becomes the portrait of the estate,' Casto says. 'Eventually, I'd love for this to be our flagship wine—our benchmark.'
Future vineyard blocks will be planted with this in mind. Casto is training 200 vines on a high-wire system meant to handle rising temperatures. Half the estate—roughly 21 acres—is under evaluation for replanting.
'The idea is to plant a block with the intention that it will always be a blend,' he says. 'The composition of the blend will reflect the distribution of cultivars planted. And that can shift over time.'
The pressures shaping Casto's work are not only philosophical. In 2024, California's wine grape harvest fell to its lowest volume in two decades, with a total crush of just 2.8 million tons—a 23% drop from the previous year. Napa Valley alone saw nearly 40 days above 100 degrees Fahrenheit during the growing season, a fourfold increase over 2023.
At the same time, expectations for sustainability have become standard. More than 90% of California's wine now comes from Certified California Sustainable wineries, and over 65% of the state's vineyard acreage is certified under environmental programs.
For Casto, these factors are inseparable from how wine is made. 'It has to work on multiple levels,' he says. 'It can't just solve one problem.'
Quarterly reports will document the process. Soil pits, trellising design, canopy orientation and clonal selection will be shared with club members. 'My opinions will change. My mistakes will accumulate,' he says. 'That's part of it.'
At Ehlers, he produces just 100 cases of Perdrix right now. But it serves as a test model. The smaller size offers control. It allows for extended aging, regular evaluation and immediate course correction. It avoids the forced consistency required in wines that must be replicated at scale. 'We need to do more, do it faster, and do it better,' Casto says.
The goal is not rarity. It is refinement. Casto says he doesn't view winemaking as a search for perfection or permanence. Instead, it is process-driven, dependent on restraint, awareness and time.
'When someone asks why I take photos, I say, because I'm afraid I won't see it otherwise,' he says. 'That's how I feel about winemaking too.'