Hot Grapes for a Hot (Cold, Hailing, Rainy) World

The article below is written by Kathleen Wilcox and was first published in Wine Industry Advisor.

It examines the very real situation of vineyards affected by climate change. Here in Aotearoa, we are beginning to see these effects with unprecedented weather events. Too much rain, too much wind at flowering, too hot and dry, an extra cyclone or two. Frost has always been a threat for many producers but this may be a bigger problem if we don’t start to tackle some of the climate changes. What can we control? What can’t we control? When will big money become the leaders of change instead of the cause?

For some vineyards, change will come too late and may be abandoned. For others, finding sites above the hotline into cooler areas will be the answer. Chile and Argentina already do this – not because of climate change, just because they have found the best sites, and it’s now also an insurance policy driven by nature.

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The climate is changing, and overall is trending warmer.

That trend is “unequivocally” tied to human activity, and is “proceeding at a rate that is unprecedented over millennia,” according to NASA. The longer and warmer growing season are linked to increased wildfire risks and drier conditions. Except when there’s frost and excess rain, which can also happen, sometimes after a year of heat waves and drought.

The science points to consistent change, which makes finding solutions tough. If we knew that certain regions were going to get hotter and drier year after year, or contend consistently with late spring frosts, excess rain in the growing season and random hail storms, we could pick grapes that would flourish in one or two of those conditions. But all of them?

Below, winemakers explain how they plan to make consistent wine in an era of flux.

Casting a Wide Net for Grapes in Alentejo

Germany grows almost 135 different varieties of wine grapes, Australia grows around 160. A single field in Portugal nourishes 189.

These experiments at Herdade do Esporão (see image at end of copy) in Alentejo began, winemaker Sandra Alves says, as part of an attempt to elevate their environmental, social, and economic efficiency. This trio of initiatives takes many forms, one of the most promising according to Alves and agricultural director Rui Flores is the 25-acre Ampelographic Field. Planted in 2010, the vineyard is home to 189 varieties—a combination of grapes native to Alentejo, the Douro, and other regions in Portugal, as well as international varieties that Flores says “show promise and potential for thriving in Alentejo.”“We want to preserve rare Portuguese grape varieties, but also identify grapes that can thrive in a variety of conditions,” Alves says. “We have learned so much from this vineyard. In 2014, we selected a number of varieties with the greatest potential to respond to our challenges, including water stress, thermal stress, resistance to pests and diseases, and varieties that were adaptable to our soils and certified organic agriculture, with the potential to meet the high standards we set for our wines.”

Alves calls the field her “lifetime project” that she hopes will ensure the “viticultural heritage for the next generation.”

Currently, 25 white and 25 red varieties have shown great environmental promise and are undergoing micro-vinifications to assess their potential as premium wines.

Revisiting Indigenous Rarities from the Past in Spain and FranceThere are more than 10,000 varieties of wine grapes on the planet, but many have been or currently are on the verge of extinction.

But in Spain, winemaker Emilio Rodríguez Canas at Terras Gauda and O Rosal in Rías Baixas has saved heirloom white variety Caiño Blanco from disappearing completely. In fact, today, Terras Gauda’s acreage encompasses 83 percent of the world’s Caiño Blanco plantings. And in recognition of the white grape’s ability to thrive in spite of climate change, the Rías Baixas D.O. has made it an officially approved variety.

“We’ve seen increasing temperatures and more hours of sunshine over the past few years in Rías Baixas, along with diseases that were not common in this area, such as oidio (powdery mildew) and moths or the green mosquito,” Canas says, adding that in addition to resisting regional pests and diseases, the grape is highly drought- and heat-tolerant.

“Caiño Blanco can be cultivated in the same soil and climactic conditions as traditional regional whites such as Albariño, Loureiro, and Palomino,” he continues. “Its main virtue is in the mouth, with tremendously glyceric, unctuous wines, dense and lingering. With lees-aging we can reinforce creaminess and complexity.”

It also features the highest acidity of all of the grapes he grows, giving it excellent aging potential and ideal for blends with other traditional regional whites, Canas explains.  

In the 20th century, France’s temperatures were 30 percent higher than the average warming across the globe, rising 1.71 degrees Celsius versus the global average of 1.33 degrees Celsius. But last year, the country’s wine industry suffered the worst damage in decades due to frost, with many harvests down by about 29 percent across the board.

Philippe Pellaton, president of Inter Rhône, says the region is expanding the number of varieties it authorizes for use in a bid for flexibility amid climate chaos.“We approved Marselan, Caladoc, and Couston as blending grapes in recent years,” Pellaton says, bringing the total number of approved grapes to 21. “Caladoc matures later, like Grenache. With it, we try to obtain freshness, and it thrives in drought. Marselan and Couston are used for color, and they also ripen later, which helps with the danger of spring frosts.”

The Inter Rhône is also working with scientists to establish varieties that can thrive in Rhône climate and soils, under drought conditions, with the ability to also withstand mildew and oidium.

“We are researching international grape varieties from Spain and Italy, and they will be introduced as an experiment in vineyards over 10 years,” he says. “Experimentation with different grapes is at the heart of our strategy in our fight against climate change, but we are still at an early stage.”

Importing Super-Resistant Old World Rarities in California and Israel  

By 2100, the average daily temperature in California is projected to increase by between 5.6 and 8.8 degrees, according to California’s Climate Change Assessment. The water supply from snowpack will decline by two-thirds. The average area burned by wildfires will increase by 77 percent.

At Brand Napa Valley, co-founder Jim Bean still focuses primarily on Cabernet Sauvignon and Cabernet Franc. But of its 15 acres under vine, about 2.5 acres are dedicated to under-the-radar (in California at least) white Italian varietals.“We work with Fiano, Arneis and Ribolla Gialla, as the core varietals in our white blend,” Bean says. “In 2019, we introduced Greco di Tufo, which added a beautiful, but subtle richness. We continue to experiment with additional varietals, including Cortese, Vermentino and Falanghina. When they become core to the blend, we plant them to our estate vineyard.”

Bean admits that part of his attraction to the regional rarities is novelty, but says he’s been heartened to see how they perform under challenging conditions.

“They thrive under stress and drought, and manage to be expressive growing in tough conditions in rocky soils,” he say. “We will continue to experiment and think creatively about how to combat environmental challenges.”

Victor Schoenfeld, head winemaker at Golan Heights Winery in Qatsrin, Israel partnered with ENTAV (France’s National Technical Association for Viticultural Improvement, the oldest and largest plant material bank in the world) on a propagation facility to explore promising varieties that would thrive in their volcanic, heavy and deep soils.

“Our soils have a high water-holding capacity and allow for very deep rooting,” Schoenfeld explains. “We have a classic Mediterranean climate, with cooling effects of high elevation. We currently work with 19 varieties, including T2 (a cross consisting of Portuguese varieties, Touriga Nacional and Tinta Cao, Gewürtztraminer and Malbec).”

His experimentations, he says, have actually changed his thinking and given him hope about the adaptability of grapes to a changing climate.

“Once, the idea of categorizing varieties as more drought resistant (isohydric) and less drought resistant (anisohydric) was a commonly accepted idea,” Schoenfeld says. “But in recent years, it has been shown that the same variety can behave in both ways, depending on soil, climate, water, management conditions. In our own vineyards, we have made varieties we once thought to be very sensitive to drought much less so as we have changed our management.”

It’s possible that 85 percent of the areas we currently grow grapes across the globe in will be unsuitable for making good wine unless we change the grapes that are grown there.

Old World regions with traditions of wine-growing dating back centuries, and New World regions where the wine production is more recent, are dipping into their own past, and borrowing from each other to figure out—in a race against climate change—what may thrive in their soil, and what doesn’t. Their findings, we hope, will create a more delicious and sustainable future for all of us.

About the writer:

Kathleen Willcox writes about wine, food and culture from her home in Saratoga Springs, N.Y. She is keenly interested in sustainability issues, and the business of making ethical drinks and food. @kathleenwillcox