Since he refuses to build more water storage facilities—and is demolishing four dams with no replacements, Gavin is making sure the agriculture industry goes belly up—and it looks like with wine people will be the first to go.
“Right now, a large majority of Napa growers use something called vertical shoot position, or VSP, which trains vines to grow up in tall narrow shoots while keeping the grape clusters hanging low to the ground.
But when a heat wave strikes, this trellis system, which maximizes sun exposure, can leave grapes sunburned or raisinated. Not only that, but the clusters that do remain can degrade, researchers found, creating wines surging with sugar, hot with alcohol and lacking that hallmark acidity and fruitiness that people expect of California wine.”
Newsom drinks a lot of wine, why does not hate California winemakers?
How winemakers are saving California’s Cabernet from climate change
By Jessica Wolfrom, SF Examiner, 10/10/22
To be a winemaker in California is to be an optimist.
Or at least, that’s the theory that animates Tom Gamble, a third-generation farmer who grows 175 acres of cabernet sauvignon, merlot and other Bordeaux varietals off Highway 29 and throughout Napa Valley.
But in recent years, a changing climate has put this optimism to the test, smothering his vines in wildfire smoke, scorching grapes in extreme heat and leaving roots searching for water.
“The heat event was not the only thing that happened this year,” said Gamble, referring to winter hail storms and bouts of bad weather that plagued his vines this growing season. “You survive all that, and then you have to survive the heat — it’s like The Old Testament, (but) it comes in more than threes.”
In some places along the North Coast, grapes quite literally cooked on the vines this summer — a trend that many fear is set to continue as temperatures rise. That’s why researchers have spent the last six years looking for new ways to bolster wine grapes against extreme heat. And now, they’ve found a solution: altering the way fruit hangs on the vine.
Trellising, for the average drinker, is perhaps not the sexiest part of winemaking. But for growers, how you manage a vine’s growth plays an integral role in how the sun interacts with grapes and, in turn, the compounds that impart a wine’s color, taste and texture.
Right now, a large majority of Napa growers use something called vertical shoot position, or VSP, which trains vines to grow up in tall narrow shoots while keeping the grape clusters hanging low to the ground.
But when a heat wave strikes, this trellis system, which maximizes sun exposure, can leave grapes sunburned or raisinated. Not only that, but the clusters that do remain can degrade, researchers found, creating wines surging with sugar, hot with alcohol and lacking that hallmark acidity and fruitiness that people expect of California wine.
“During these heat waves, these VSP trellises provide zero protection,” said Kaan Kurtural, professor of viticulture and enology and an extension specialist at UC Davis and lead author of a new study that looks at the issue. “Because the fruit is low to the ground, you also get heat reflecting back into the canopy and clusters.”
Researchers have instead proposed switching to what’s called a “single high wire trellis system,” which keeps berries higher off the ground and under the shade of more leaves.
This system not only protects berries from the harsh sun but also preserves chemicals that contribute to the quality of wine. The high wire system also makes grapes easy to harvest, a key concern among growers, and can save on labor costs, researchers found.
Still, it’s unclear how widely adopted these findings will be throughout Napa Valley — a place steeped in tradition and near mythological lore.
“Napa growers, they don’t want their vineyards to look like a Central Valley vineyard,” said Cliff Yu, an assistant professor of viticulture at California State University, Fresno, and one of the authors of the study. “They just don’t want that image.”
By that, he means the image of the mass-produced grapes grown further south, where many vineyards already use single high wire systems to beat the heat.
But it also comes down to approach. Winemakers like Gamble say trellising is low on his priority list. Instead, he’s focused on what’s going on underfoot: his soils.
“Having to adapt to changing climate, soil health, I think, is where our biggest opportunity lies,” said Gamble. “Learning how to regenerate soil complexity means changing the way we farm.”
Regenerative farming is a complicated and expanding field, but in general, it involves things like growing cover crops, reducing tilling — the stirring up of the soil — and “waking up” of the dormant microbial organisms living underground.
“There’s more microbes in a teaspoon of soil than there are human beings on the planet,” said Gamble. “And most of them are dormant.”
If we think of the soil like we do our guts, regenerative farming is basically a probiotic for the soil, Gamble said. “If we can get our roots to have a healthier soil environment, you’re going to have greater root development and greater nutritional uptake. And ultimately, that means more photosynthesis, and thus more chlorophyll storage.”
Increased storage leads to greener leaves and stronger plants, and Gamble posits the stronger the plant, the better suited it is to take on extreme heat or other harmful weather conditions.
But this theory is being challenged by a protracted drought that has sapped the soil of badly needed moisture. Complicating matters further, recent water curtailments and the implementation of the Sustainable Groundwater Management Act, which limits farmers’ ability to pump groundwater, have meant that winemakers are facing more strains on their farms than perhaps ever before.
“We just don’t have that kind of water that we can use anymore,” said Yu. “People that are growing grapes or all the other crops cannot pump as much water as they want. So they really need to incorporate water conservation practices in their farm.”
Despite all this, winemakers along the North Coast, which encompasses Lake, Marin, Mendocino, Napa, Sonoma and Solano counties, are so far faring OK, noted Yu. And a little water stress can impart more intense flavors in the wine, he said.
Still, the odds are increasingly stacked against farmers. And while trellising and irrigation management alone won’t save California’s wine from a warming world, both Yu and Gamble say Napa Valley wines are here to stay.
“The thing about Napa and the North Coast wine community is, sometimes it’s slow to adapt, but it’s very curious,” said Gamble. “There’s a lot of innovation always being tried here, and there’s so much damn money at risk that people are going to try to figure something out to make it work.”
