Terroir up there

Few winemakers ever get so close to the sun while doing their job as Randle Johnson. The Napa County resident works with The Hess Collection, a wine company that owns vineyards in California and in Argentina. Johnson makes wine from grapes grown high in the mountains, in the province of Salta—and at just under two miles of elevation, Hess’s Andean vineyards are the loftiest in the world.

“We’ve taken some risks by planting that high up,” says Johnson, who spends about six weeks of each year in Argentina. He says the region is subject to high danger of frost, which can destroy a vineyard’s fruit.

But the risk may be worth the results. Johnson says some of the best malbec and torrontés, a white grape, grown for the Hess Collection’s Colomé label, come from vineyards between 8,500 and 9,300 feet, in the north end of Argentina’s Calchaquí Valley. At such an altitude, Johnson explains, the intense radiation from the sun thickens the fruit’s skins. This is a physiological attempt by the plant to protect the developing seed. For the winemaker, this means densely packed tannins, more color in the wine, and richer flavors.

Indeed, many winemakers recognize the value of elevation. Some are looking upward for new places to grow grapes as climate-change forecasts show low-lying valleys becoming too hot in the next few decades to make top-notch wine. Others—like Johnson—simply believe that higher elevations, with blistering sun and chilly nights, can produce better wine than lower vineyards.

But the climate of northern Argentina’s mountains is very unique, allowing for cultivation of Mediterranean plant species at elevations that would kill them elsewhere. If grapes were planted in California at altitudes equivalent to the Calchaquí Valley, a grower would be looking at regions like the Desolation Wilderness or the slopes of Mount Lassen—and the vines probably would fail to grow entirely.

In fact, Phil LaRocca’s Forest Ranch vineyards, though at just 2,600 feet, are higher than most others in the state. Such an elevation, LaRocca says, is enough height to cause frost damage in many seasons when growers lower in the Central Valley experience none.

“This is really almost as high up as you can go in Northern California,” he says.

But with the risk of crop loss each spring comes the benefits of intensified flavors, LaRocca says. During the summer, when daytime temperatures can spike to 90 degrees around LaRocca Vineyards, nights may plunge to 40. This helps the development of acids that balance the taste of a wine’s sugar, tannins and alcohol.

“The Bordeaux varieties, like cabernet franc and cabernet sauvignon really do better with that elevation,” he says. “A lot of cabs grown down in the Central Valley don’t have the classic cab intensity.”

Gilian Handelman, director of education for Jackson Family Wines, says it takes only 1,000 feet, or a little more, of elevation to make a discernible difference in a wine’s quality. She recently helped arrange a small San Francisco tasting of high-altitude wines. The four selections were grown at anywhere from 1,000 feet to 1,800 feet, on steep slopes. At that elevation, lack of water and the presence of bedrock and coniferous trees produce well-structured, edgy wines, she says.

“They aren’t better than lower elevation vineyards, just very different,” she says.

In parts of Portugal, Spain, Italy, Oregon and other regions, winemakers are investing in properties 3,000 feet and more above sea level as a means of mitigation against climate change.

At the north end of the Calchaquí Valley, however, the Hess Collection’s high vineyards may be immune to the immediate effects of any warming patterns. But it isn’t even clear, yet, that the highest of their vines will produce good fruit. Johnson says they are still experimental and have not yielded a crop yet. What is certain, Johnson says, is that these vines of pinot noir and chardonnay are the highest vineyards in the world, at 10,240 feet above sea level.

“But we don’t really care about that,” Johnson says. “We’re interested in knowing we can make and bottle good wine from that region. Once we do that, then we’ll put [elevation] on the bottle.”