Wine Chronicles: Can Carneros Cabernet Be Napa’s Future?
By Dan Berger
Dan Berger reflects on a historic 1977 Carneros Creek cabernet to explore how Napa Valley's shifting climate zones are reshaping where and how cabernet can be successfully grown. With the valley's core warming into Region 3 and even Region 4 zones, longtime grower Francis Mahoney and winemaker Steve Matthiasson are turning to Carneros as a viable cool-climate refuge for balanced, structured reds. Matthiasson’s new Cressida Vineyard project signals a return to “old school” styles, potentially extending Carneros’ legacy in the face of climate change.
NAPA VALLEY, Calif. — One of the finest wines I ever tasted was a 1977 cabernet from Carneros Creek Winery. The fruit that made that wine was from Tony and Jo Ann Truchard’s Carneros vineyard in Congress Valley. The winemaker was Francis Mahoney.
A few days ago, I had lunch at Boon Fly Café with Mahoney and his winemaker, Ken Foster. That wine came up in conversation. Francis was pleased I remembered it, and he said he believed that Carneros was one of the solutions to global climate change for cabernet sauvignon producers who now grow all of their fruit in the ever-warmer center of the Napa Valley.
“If global climate change increases temperatures in the center of the Napa Valley as expected, producing historically accurate cabernet will no longer be possible there.” — Dan Berger
It is well-known that increasing temperatures in most wine areas worldwide will make a serious impact in the style of wines that can be produced. This recently was acknowledged by UC Davis’ Department of Viticulture and Enology
Back in the 1950s, UC Davis devised a five-level climate zone identification system. The index said most of the Napa Valley was a Region 2, relatively cool with warm enough pockets to ripen cabernet. (Region 1 was coolest.) This analysis was pioneered by A.J. Winkler, and his chart was named the Winkler Index.
Winkler and a team, using data that existed at the time, employed an extremely complex mathematical formula for growing degree days (GDD) and measured heat accumulation for vine growth during the growing season. It used approximate start and end dates that existed at that time.
But a lot has changed. It is now 70 years later. And a few weeks ago, UC Davis announced that it was revisiting the Winkler Index to determine how it should now be viewed. As for Napa Valley, UC Davis estimated that almost the entirety of it now is Region 3, significantly warmer, and that some parts of the valley are now Region 4, which is thought to be too warm to grow cabernet properly.
This is where Mahoney comes in. He is one of the best grape-growers in Carneros, with vineyards that straddle the county line between Napa and Sonoma, just off Ramal Road. He grows several varieties of grapes and is best known for his chardonnay and pinot noir, which is to be expected since most of his vineyards are cooled by breezes from San Pablo Bay.
However, his experience with cabernet, dating back to the early 1970s when he became one of the first to pioneer growing grapes in Carneros, told him that recent temperatures in the heart of Carneros might be perfect for cabernet specialists.
For many years, Francis also owned approximately 50 acres of vines that are higher in altitude than his main ranch and that are nearer to the Truchards’ property. It is a rocky hillside vineyard that Francis long has said was extremely difficult to farm. And it became a problem once he did some serious aspect analysis and discovered that the high winds on the property were causing photosynthetic ripening problems.
He said some row orientation was improper, which caused ripening to be retarded. Years ago, he began doing complicated row reorientation, which was not only costly and arduous but time-consuming. Foster said that some of the reorientation created rows that had only two vines.
Challenge your vocabulary with this week’s mystery word. Submit your answer in the poll, and check the bottom of the page for the correct answer.
Mahoney finally solved that problem four years ago: He sold the ranch. The buyer was Steve Matthiasson, whose name immediately rang bells for me. In fact, I couldn’t think of a better buyer for this ranch because Steve is one of the few winemakers in California who understand the need for structure and balance in red wines. And he is planning to put red-wine grapes on that property.
Things got even better for me after I spoke with Steve and he said he was planning on changing the varietal mix of the vineyard and would plant more cabernet sauvignon and related varieties.
If global climate change increases temperatures in the center of the Napa Valley as expected, producing historically accurate cabernet will no longer be possible there. But Carneros is another story, proven by the earlier Carneros Creek cabernets.
A recent story here on the search for cooler regions spoke of how cabernet would need greater attention from growers as we move forward. Steve has taken an enormous step toward in continuing his quest to make great structured cabernet.
His present vineyard location, partway up the Mayacamas Mountains, allows him to craft elegant and historically relevant cabernets that have the potential to age in a wine cellar for decades but also the balance to work beautifully now with appropriate foods.
Steve is calling this ranch Cressida. His website says this:
“We purchased the Cressida Vineyard along with our partners Perry Tam and Laura Yip in 2022. It is planted along the spine of a ridgetop in the upper section of Los Carneros, overlooking the Bay, with the San Francisco skyline clearly visible across the water. It receives the perfect balance of warm sun and cooling Bay winds, straight off the Pacific and through the Golden Gate,” the website says.
“The soils are shale from an ancient inland sea — the vineyard is the foot of the Mayacamas, with the Cressida Vineyard at the base and Mount Veeder at the top. Raptors hover overhead, riding the winds thrust up as the Bay breezes meet the Cressida hillside.”
Shale is known to provide excellent drainage.
“The vines are much less vigorous [than in other areas] and they are very close to being dry-farmed,” Steve said. He anticipates “cool climate ripeness” and expects wines of excellent complexity.
One of the first wines to come off this project is a 2022 merlot, which has only 13.% alcohol. There is also Vermentino and soon there will be cabernet franc. The merlot intrigues me because one of the finest merlots I ever tasted was a 1984 from Cuvaison, the fruit for which came off Cuvaison’s property just across the Carneros plain closer to San Pablo Bay.
Matthiasson said he anticipates “old school” styles of red wine that were not only voluptuous but distinctive.
I’m extremely interested in this new project. We will have a report on it as soon as a Matthiasson Carneros wines, designated Cressida, become more commercially available.
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Dan Berger has been writing about wine since 1975.
Wine Discovery:
2023 Linda Vista Vineyard Chardonnay ($38, 3,044 cases) — Farmed organically in Napa’s cool West Oak Knoll, this estate chardonnay from vines planted in 1989 layers citrus oil and apple skin with hints of white tea, dried chamomile and a faint seashell salinity. The palate carries a creaminess, like the texture of lemon custard, lifted by acidity that recalls biting into just-ripe stone fruit. At 12.5% alcohol, it’s poised and refreshing. Pair with roast chicken, crab cakes or raw shellfish. — Tim Carl
Today’s Polls:
This Week's Word Challenge Reveal:
The correct answer is B: "Pollination by wind."
"Anemophily" is the process by which plants are pollinated through wind rather than insects or animals. It’s common in species such as grasses, conifers and some trees that release large amounts of lightweight pollen into the air. While grapevines are primarily self-pollinating, wind plays an important role in vineyard health — especially in places such as Carneros, where breezes from San Pablo Bay influence ripening, air flow and disease pressure. Understanding wind's role helps with decisions like row orientation and canopy management.
The word comes from the Greek "anemos" (wind) and "philos" (loving) and first appeared in botanical texts in the mid-1800s. Though more common in plant ecology than viticulture, the concept highlights how natural forces like wind shape agricultural practices — particularly in coastal or elevated regions where airflow can make or break a vintage.
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