For now, in Napa Valley, there’s no doubt that Cab remains king. In 2019, 64.6% of all red grapes harvested were Cabernet Sauvignon, with an average price of $7,941 per ton, the highest in history, per the 2019 Napa County Agricultural Crop Report.
As the reality sets in that the region is getting hotter and drier, increasing the already pressing challenges of water, fire and disease, producers look to diversify once again.
What’s Threatening Cabernet?
In a 2018 Napa Vintage Report, Dr. Greg V. Jones, director of the Evenstad Center for Wine Education at Oregon’s Linfield University, wrote that from 1895–2018, California’s growing seasons warmed an average of 2.3˚F.
Climatologists like Jones predict Napa Valley could move from being classified predominantly as Winkler Region III and IV, ideal for grapes like Cabernet Sauvignon, to a Region V, the warmest of all. This index is based on the sum of daily temperatures above 50˚F between April and October (in the Northern Hemisphere).
“We have the opportunity to learn and discover, to bring in and open people’s minds to drink other things.” —Dan Petroski, winemaker at Larkmead Vineyards in Calistoga
All of this means that the long-term survival of Cabernet is on a lot of people’s minds.
“Larkmead has had over 30 varieties here, including Zinfandel, Petite Sirah and Charbono,” says Dan Petroski, winemaker at Larkmead Vineyards in Calistoga. “It was Larkmead’s 125th anniversary last year. How is this place going to evolve?”
Any wine that calls itself Napa Valley Cabernet Sauvignon must contain 75% of the grape, which leaves opportunity for other grapes to be used in blends. These could be varieties less inspired by warm regions like southern Italy, South of France, Spain and Portugal.
“I’m looking to more heat-resistant grapes, but also looking at world-class wines and what they’re made of,” says Petroski. “We have the opportunity to learn and discover, to bring in and open people’s minds to drink other things.”
Adaptations in the Vineyard
Winemakers and growers are feeling the squeeze between bloom and harvest dates, the contraction of ripening time amid warmer, drier weather. Two main questions are being asked: How can we protect our most prized possession from changing weather and weather extremes? And, should we think about planting varieties other than Cab?
“It is hard to both be focused on the present with an eye to the future, but, of course, without any clarity of what exactly that future will look like,” says Aron Weinkauf, winemaker and vineyard manager of Spottswoode in St. Helena.
Weinkauf, who oversees the property’s 38 acres of organic vineyards, is well aware of the dramatic changes that are happening with the climate. The five hottest years on record in Napa Valley have all been since 2015.
He says the variables are becoming more extreme and the frequency of variations more common, which makes it hard to plan for consistency. Trellising, head modifications, misting, shade cloth and irrigation practices are all being addressed.
At the same time, Weinkauf says that a plant’s desire to survive and adapt is often underestimated. That includes Cabernet Sauvignon. He’s trialing different rootstocks for Cab, as well as many other varieties like Alicante Bouschet, Tinto Cão, Touriga Nacional, Souzão, Mourvèdre, Valdiguié, Carignan, Marselan, Manseng Noir, Arinarnoa, Falanghina and Assyrtiko. He seeks to increase his pool of new wines and blending components, and also build his understanding.
“Climate change is not just about warming, but rather having greater climatic extremes, some hot, some dry, some wet, and new pests and pressures,” says Weinkauf. “I always think that biodiversity is the only real buffer to these trends
“Each of those yearly ups and downs might favor or disfavor the components we look for in great wine fruit, complexity, color, acidity—and as growers, we want them resilient to rot, water stress, mildew and other diseases and pests.”
For Pine Ridge Vineyards in Napa Valley, Nicolas Quillé, MW, Crimson Wine Group’s chief winemaking and operations officer, says it’s not only important to plant experimental varieties, but to plant Cabernet Sauvignon in the cooler pockets of the region as well. At Pine Ridge, Cabernet Sauvignons are made from Howell Mountain, Oakville, Rutherford and the Stags Leap District.
“I’m concerned about climate change and the Cabernet business in the Napa Valley,” says Quillé. “We are feeling the effects of intense heat and sun, the exposure lessening color, the grapes becoming more and more tannic, and flavors moving toward the jammy side. The acidity is going down, and the alcohol is going up.”
Changes in the Blends
Quillé says that the financial investment is too high to move away from Cabernet entirely. He says that viticultural practices and techniques can mitigate the heat, and that Napa wineries will have to make it work. With the 25% of other varieties allowed in Cab blends, he seeks to boost fresh fruit character through grapes that ripen later, have higher acidity and lower sugar, and are more drought resistant.
BV Ranch 12 in Calistoga, the largest estate of Beaulieu Vineyards, has Touriga Nacional, Charbono, Tempranillo and Petite Sirah. A former Christian Brothers site, it was planted to those varieties long ago. Winemaker Trevor Durling bottled the Touriga Nacional on its own in 2018.
“Napa is amazing at growing lots of things. The beauty of the wine industry is we adapt. We must adapt, and we will. The question is, how fast?”—Kale Anderson of Kale Wines
In 2022, Quillé intends to plant an experimental vineyard in Oakville to five yet-to-be-determined varieties. On his radar are Alicante Bouschet, Negroamaro, Marselan, Lambrusco and a Russian Crimean hybrid that’s frost and cold resistant, as well as heat and drought resistant. All would need to be quarantined and cleaned up before planting.
He’s also planted Cabernet Sauvignon in Carneros, cooler climes that primarily grow Pinot Noir and Chardonnay. So far, 10 acres of Cabernet are in the ground, with another 40 acres planned.
“I think Tempranillo thrives in more moderate weather, where the flavors can fully develop and the wines present rounder tannins and beautiful floral notes,” says Diogo-Draper. “These vines are planted in some of the cooler sites of the property granting the grapes hang time, while maintaining varietal character.”
Meanwhile, Kale Anderson, who got his start at Colgin Cellars, has been a proponent of Rhône varieties in Napa Valley since he made his first barrel of Syrah in 2003.
In 2011, he had Grenache and Mourvèdre planted for him in Rutherford, but only after he signed a 10 year contract that guaranteed he’d buy the grapes. He makes both a red and rosé from the site.
“It’s never good to have a monoculture in any ecosystem,” he says. “Napa is amazing at growing lots of things. The beauty of the wine industry is we adapt. We must adapt, and we will. The question is, how fast?”