Along the west bank of the Garonne river, in the Bordeaux region of France, lie some of the world’s most celebrated vineyards. Names like Château Margaux and Château Ducru-Beaucaillou, with their $1,000-a-bottle Grand Crus, have been producing famous French blends that predate Napoleon III. But on the left bank, in the town of Villenave-d’Ornon, is a much less well-known vineyard, situated on a modest plot behind the University of Bordeaux’s Science Institute of Vine and Wine. Production at VitAdapt is meagre – about a hundred bottles a year. The public will never get the chance to sample any of it. And yet its reputation is growing.
VitAdapt cultivates many more grape varieties than your typical vineyard. “We have planted 52 varieties here, from all over,” says Cornelis "Kees" van Leeuwen, a professor of viticulture at the institute's Bordeaux Sciences Agro, and a manager of the VitAdapt initiative. By contrast, commercial producers of Bordeaux wine are restricted to an approved list of just 13 grape types and often work with considerably fewer.
That VitAdapt fits so many varieties on its small, one-hectare patch won’t win it any awards for viticulture design. Scanning the field at eye level, you can see the grapes are densely bunched. Rows of Chardonnay vines mingle with Malbec, which tangle with Tannat, a red wine grape that has French origins but is now widely grown in Uruguay. A bit further along are Portuguese, Spanish and Italian grapes, as well as a hard-to-pronounce Georgian variety, Rkatsiteli.
Every inch of the vineyard is put to work on monitoring how environmental factors affect the soil and the vines – what winemakers refer to as terroir. Sensor ribbons wrap around the vine trunks to measure sap flow, an important indicator of how each plant handles moisture (or lack thereof). Spaced strategically on the ground are white containers, no bigger than a shoe box, that house a data logger.
The eclectic mix of grape varieties is the whole point of VitAdapt. Van Leeuwen is among a growing cadre of scientists who believe that the wine industry’s best chance at surviving environmental challenges is to exploit the diversity of the wine grape – reversing the prevailing industry practice of banking on an ever smaller selection of grapes that have come to define many of our favourite wines, such as Chardonnay, Pinot Noir and Merlot. For regions being upended by climate change – which is just about everywhere – these scientists say it’s time to swap the familiar (and overwhelmingly French) grape types for hardier varieties that can handle hotter, drier and less predictable weather cycles. Adaptation is becoming a particularly urgent matter for the Bordeaux wine industry, which at a value of €4 billion (£3.6 billion) is the largest in France.
Using data, statistical modelling and chemical analysis, plus a lot of knees-in-the-dirt trial and error – and sip-and-spit dégustation sessions – the VitAdapt team has begun to identify promising alternative grape varieties from among the dozens it cultivates: breeds tough enough to withstand drought, soaring temperatures, extreme weather events and new diseases, yet tasty enough for the most discerning aperitif crowd. “We are not inventing anything new here,” he says. “We are just going back to the common sense that people have used for ages and, in many cases, have forgotten.”
Vitis vinifera, the common wine grape vine, is one of the earliest domesticated fruit crops on the planet. Humans began coaxing wine out of this hardy species over 6,000 years ago in the Middle East – and war, commerce and religion have carried it around the Earth. The story of wine is the story of civilisation. Vitis vinifera does best where the average temperature sits between 13°C and 21°C, but we’ve been pushing the species to its limits for millennia with excellent results; quality wines have emerged from North Africa, Swiss alpine slopes, and even cool, damp England.
The wine grape is the most valuable crop on the planet. It’s also remarkably prodigious. There are at least 6,000 varieties of Vitis vinifera, with previously undocumented cultivars (varieties produced by selective breeding) being identified all the time. But despite this, only a dozen or so – mainly French – grapes make up 80 per cent of the wine on the global market, and many are simply not fit to withstand warmer, drier climates. Varieties such as Merlot, Chardonnay, Pinot and Cabernet dominate vineyards from Napa to New Zealand, despite the climatic differences and the cultivars’ French ancestry. But these grapes were never meant to be grown everywhere.
A 2018 research paper in the online journal Nature Climate Change decried the industry’s pivot in recent decades away from a tried and trusted grape selection strategy that exploited Vitis vinifera’s rich diversity, towards one that seems bent on turning it into a monoculture. “Wine producers’ increasing reliance on a few major varieties translates into a global market that is investing in an increasingly limited portfolio at exactly the time when a large diversity of varieties is most needed,” the researchers wrote. “This narrow focus means a narrower range of critical traits related to climate, which in turn reduces the flexibility of most vineyards to adapt to climate change.”
The paper re-opened a debate that had been kicking around the wine world for the past decade: that a great redrawing of wine maps is needed, one that re-emphasises the many regional varieties that have been pushed into obscurity by global wine trends.
Elizabeth Wolkovich, an associate professor in forest and conservation sciences at the University of British Columbia in Vancouver, Canada, is one of the paper’s authors. She says she’s concerned that unless vintners start experimenting with new varieties, their wines will suffer. Climate change may even run some out of business. “My assertion is that we should start thinking about how to adapt now,” she says.
Wolkovich shares a general rule for the adaptation of climate-sensitive crops, whether it be a banana or a wine grape. “It’s really hard to predict what will take down a crop, except that crops with lower diversity will have fewer mechanisms to deal with the problem,” she says. “What you want is diversity in a population, so that when a new threat comes in, whether it be a pest that the crop has not seen before or a new climate regime that’s so outside the norm it acts like a major cataclysm, you want to have some part of that [crop] population that just happens to have an inherent resistance.”
Climate change messes with the phenology, or growth cycle, of Vitis vinifera, and therefore with the quality of the wine it produces. Today’s hotter, drier growing seasons push forward the maturation process by days. For centuries, winemakers toiled to improve the ripeness of their grapes. Now, climate change is forcing them to do everything in their power to delay it. A basic rule of viticulture holds that when wine grapes ripen too soon, they contain excessive sugar levels – “resulting in wines with high alcohol content, lacking freshness and aromatic complexity”, Van Leeuwen says. The result, at least in less expert hands, is an alcoholic fruit bomb.
But the wine grape is a diverse species in terms of phenology. “There are huge differences between later- and earlier-ripening varieties,” says Van Leeuwen. “And that also makes the vines more adaptable to different climatic situations.”
From the thousands of Vitis vinifera varieties out there, some are well-suited to adapt to the changing climate of a particular region. Their phenology is remarkably steady and reliable, even when the growing season is not – and they taste good. The problem is, much of this local knowledge was lost in recent decades as producers increasingly jumped on the Cabernet-Pinot-Merlot-Chardonnay bandwagon. Van Leeuwen is determined to rediscover these forgotten varieties, starting in Bordeaux.
Van Leeuwen discovered wine at an early age through his father, a connoisseur. Growing up in the Netherlands, he came to see wine as his ticket out of his home country. At first, he wanted to write about the subject, then decided it would be more interesting to learn about growing. He studied in Champagne and Burgundy, before settling in Bordeaux in 1983, a few years out of school.
The Dutchman quickly impressed the locals with his knowledge of wine. By 29, he was managing one of Bordeaux’s most prestigious vineyards at Cheval Blanc, in Saint-Emilion. There he could see up close the impact of climate on the quality of each vintage. He returned to study to earn a PhD at Bordeaux Sciences Agro, researching terroir and climate. The subject drew the attention of the Saint-Emilion growers' association, which helped fund his work. He looks back on those times, in the early 1990s, as a different era. “Nobody was talking about climate change then,” he says.
That all changed at the end of the decade, when Hans Reiner Schultz, a German plant scientist who had worked with winegrowers on four continents, dropped a bomb on the wine world. In a 2000 paper, he contradicted the prevailing belief that a hotter, drier climate always makes for better wine. Schultz saw that elevated levels of ultraviolet B rays were transforming grape composition, messing with the metabolites responsible for giving grapes their flavour.
Schultz’s work was hugely influential on Van Leeuwen, who started thinking about grape type varieties as an adaptive measure to forestall the worst effects of climate change on the winemaking process. He knew his suggestion – experimenting with new grape varieties (or, even better, grafting them on to particularly robust root stock clones) – was a radical one, and it took much of the 2000s before he found funding to test his hypothesis at VitAdapt.
For all winemakers, the key is understanding how a grape adjusts to its environment during each phase of the growing cycle. When I visit VitAdapt in July, it is during the crucial veraison stage, at which the bunch ripens from hard green beads to sweet, colourful berries (in red varieties) or transparent ones (in white). Touring the site, Van Leeuwen leans down several times to move aside vine leaves and reveal the condition of the grapes. Some are well into veraison; others are still weeks off.
Of the four major phenological stages (budbreak and then flowering in the spring, followed by veraison and fruit maturity), veraison is the best indicator to determine a vine’s long-term prospects, Van Leeuwen explains, as it is particularly sensitive to climate change. As any grower will tell you, if veraison comes too soon – as is the case in particularly hot summers – the harvest will be pushed forward on the calendar. Until now, winemakers could use this information to plan and adjust a few weeks out and maybe forestall the harvest by a few days. Van Leeuwen wants to go further – years out. “If you measure veraison data rigorously for each variety, you can build a model that will tell you if it has a good chance or not of adapting to a warmer climate,” he says.
VitAdapt picks the fruit from its vines selectively throughout the summer and, under the supervision of Agnès Destrac-Irvine in the VitAdapt laboratory, tests how each variety accumulates and breaks down the basic flavour and aroma components at various points in the cycle from veraison to maturation. The rest of the crop is left on the vine until fully ripe, when it is picked, weighed and counted, before being crushed into juice. Some is set aside for small-scale vinification, while the rest is poured into beakers to measure levels of sugar, organic acids and other metabolites that give wine its aroma and flavours.
VitAdapt already has a decade’s worth of data that points to the varieties that will best adapt to Bordeaux in the coming decades – and those that won’t. Van Leeuwen ranks the potential winners and losers in a graphic that he often presents at viticulture and climate conferences. It details the 52 wine grapes in the VitAdapt portfolio, and their average veraison dates. The disparity is remarkable. In the bottom left are the early-ripening grapes, the ones most at risk from warmer, drier climates. They include Pinot Noir, Chardonnay, Sauvignon Blanc and the Swiss white variety Chasselas. Those in the late-ripening “safe zone” include a local but rarely used red, Petit Verdot, plus the Greek variety Xinomavro and Carignan, a Spanish grape that was popular in southern France in the 1980s – before growers dug up the vines and replaced them with Merlot, which was emerging as the world’s favorite wine grape. Petit Verdot reaches veraison on average, 25 days after Chasselas, the earliest ripening grape variety on Van Leeuwen’s list, and a good two weeks after Merlot.
The VitAdapt team uses the data it collects to build phenological models that Van Leeuwen hopes will guide winegrowers in the future – which he sees as a sort of GitHub for grapes. “These phenology models will work for regions around the world, not just Bordeaux,” he says. “Models like this will help growers choose the varieties that work best, given the climatic context in their part of the world.”
In Bordeaux, where the annual average temperature has climbed more than one degree Celsius since the 1980s, growers have a conflicted view of climate change. At first, the hotter, longer summers were welcomed. Vintage after vintage produced fabulous wines – lush, potent reds that wine critics feted and consumers stockpiled. But then 2017 happened. A freak late-April frost devastated the crop. Production in Bordeaux crashed by 295 million bottles. Growers talk about it with horror. “When you lose 40 per cent of your income in ten minutes, you remember,” says Christophe Chateau, communications manager for the local wine board, Conseil Interprofessionnel du Vin de Bordeaux (CIVB). The worst-hit grape was Merlot.
If wine in Bordeaux is a religion, then Merlot, accounting for 66 per cent of the region’s red wine grape crop, is its patron saint. But for over a decade, Van Leeuwen has been warning his renowned winemaking neighbours that the grape’s days are numbered. Based on VitAdapt data, he predicts that Bordeaux’s Merlot has another 20 years, perhaps 30 at the most. Beyond that? “Big difficulty.” Cabernet Sauvignon is, by volume, the number two red grape variety in Bordeaux. Van Leeuwen has concerns – milder, but still doubts – about the future of Cabernet after 2040.
If local growers were unfamiliar with Van Leeuwen’s work at VitAdapt before the devastation visited on the 2017 vintage, they know about it now. “We’re watching Kees and his work very closely,” says Bordeaux-based oenologist Arnaud Delaherche.
Delaherche works at Château La Tour Carnet, about an hour’s drive north of VitAdapt, in the appellation of Haut Mèdoc. Wine-lovers the world over make the pilgrimage to this celebrated Bordeaux vineyard to sample its prize-winning creations, snap selfies under the 11th century watchtower and marvel at the functioning moat and drawbridge that have succeeded in repelling invaders dating back to the 15th century and the Hundred Years' War. The main threat these days, Delaherche says, is nature.
Delaherche was hired by wine magnate Bernard Magrez to run research and development across his Bordeaux wine estates in the spring of 2017. Asked about his work, his mind returns to his first month on the job. Overnight on April 27, temperatures plunged below zero. “I still remember the day,” he says, with a pained look. He motions to a slope of Merlot vines where the damage was most concentrated, just beyond the gated entrance. “Here, here, here. Fifty percent of production – pfft.” Elsewhere on Bordeaux’s left and right banks, frantic winemakers set up "burn barrels" between the vines to keep the foliage, shoots and immature grape nubs from freezing. But by morning, lush rows of Merlot and Cabernet Sauvignon vines were reduced to barren stumps.
There’s never a good time during the growing season for an exceptional cold blast. This one occurred early in the cycle. Some Bordeaux vineyards experienced re-growth, but then the vines were off schedule. Some vineyards had to do multiple harvests of the same variety. Just about everybody agrees it was one of the worst seasons in memory.
Late-April frosts are a once-in-a-generation phenomenon. Or were. Lately, each season has brought with all kinds of freak weather – weeks of punishing drought or, as occurred in the summer of 2019, 40°C-plus heat waves in June and then in July (with hailstorms in-between). Growers have developed all kinds of hacks to maintain the sugar and acid balance of the grapes. By pruning less of the protective leaf canopy or allowing the trunk to grow taller above the soil, for example, they can regulate temperature and levels of ultraviolet radiation. In places where water restrictions are no issue, drip-irrigation devices tuned to real-time weather data are the norm, and big data analysis is everywhere. But smart tech in the vineyards can only do so much to reduce losses in unstable years. In 2017, the French grape yield dropped by 500,000 tonnes compared with 2016.
Delaherche says the combination of new tech and the various adaptive practices applied during growing season can only buy winemakers so much time. Besides, he adds, they are little use in combating a cataclysmic freeze like the Merlot-killer of 2017. That event has convinced him the answer is to find more climate-suitable grapes.
In the mid-afternoon sunshine, Delaherche shows me part of the grounds that most tourists overlook. Just outside the front entrance, near the wine shop parking area, lies a 1.5-hectare plot of unusual grapes – 75 varieties in all, from French favourite Syrah to Spain’s beloved Tempranillo, the lesser known Swiss red Gamaret and the sweet North African white Muscat of Alexandria, popular in Cleopatra’s time. Delaherche collaborates closely with Van Leeuwen’s team, and the two share the same objective: to find, through painstaking analysis, a grape that can save the Bordeaux blend from climate change.
The strongest candidates wouldn’t replace the Merlot or Cabernet Sauvignon, at least at first. Instead, the newcomers would be added to the mix to fortify the blend. It may not even be a French grape that does the trick. There are limits, however. Whichever new grape makes the final cut, it cannot impact what winemakers call typicity, or typicité. “When you open a bottle of Bordeaux you expect a certain typicité,” Delaherche says. “This cannot change.” Whatever the recipe, it has to taste like a classic Bordeaux wine. “Maybe in the future, the Merlot and Cabernet will be OK – maybe,” he says, sounding unconvinced. “Or maybe we need to change the grape variety. What is the next grape for Bordeaux? The Tempranillo? The Syrah? I don’t know. That’s why we’re doing this.”
Château La Tour Carnet only produces a couple of bottles of these unusual wines, none of which are for sale (under Bordeaux’s strict quality control rules, most of the grape varieties Delaherche is growing on the experimental plot cannot be put in a bottle, labelled Bordeaux and sold to the public). And the vines are so young that Delaherche doesn’t expect any interesting wines for another few years. Still, this little patch of grape vines is already the talk of this part of Médoc. “There are some growers who think we’re crazy,” he says. But he is also getting a new type of visitor: local winemakers. “They’re curious. They want to see these grapes for themselves.”
In France wine is highly regulated, and in tradition-bound Bordeaux the idea of introducing foreign grapes to the winemaking process would have been heretical a few years ago. But up and down the region, Van Leeuwen’s message is beginning to take root.
“The Merlot and Cabernet are not good for such high temperatures,” says CIVB’s Christophe Chateau. “What will the climate be like in the next ten, 20, 30 years? Maybe we are going to have to use new grapes that are more resistant to high temperatures. This is the point: which grapes are best for a changing climate? This is what we want to know now.”
Earlier this year, CIVB voted unanimously to introduce seven new grape varieties – four red and three white – into the production of “AOC Bordeaux” and “Bordeaux Supérieur” wines. The move still has to be approved by France's national oversight body, the Institut National de l'Origine et de la Qualité, which could come early next year. Still, van Leeuwen sees it as a vindication for VitAdapt’s work. All seven are grown on the VitAdapt plot. One is the late-ripening Portuguese variety Touriga Nacional; another is Albariño, a staple of Spanish and Portuguese wines since at least the 12th century.
Any newly approved grape would be in the minority at first. Under the CIVB proposal, no more than 10 per cent of the final blend of a Bordeaux wine could be composed of the new grapes, and no more than five per cent of a vineyard’s overall plantings.
“It’s the most significant rule change that anyone in Bordeaux can remember,” says Florian Reyne, managing director of the AOC Bordeaux and Bordeaux Supérieur appellations.
The wine industry has faced crises before, and it has adapted. It is this history, more than anything else, that gives scientists such as Van Leeuwen reason for hope. In the 19th century, the Phylloxera aphid that feeds on the roots and leaves of most kinds of Vitis vinifera grapes, devastated much of the European, and particularly French, wine industry. The sector eventually rebounded, but only after a global network of botanists and growers joined forces to counter the threat. This knowledge exchange between the old world and the new, between the scientific community and the marketplace, has endured ever since.
Winemakers around the world pay particularly close attention to what happens in Bordeaux; the style of wine produced here is copied the world over. And Bordeaux’s push to restore the diversity of Vitis vinifera as a hedge against climate change is beginning to be understood and embraced elsewhere too. “The fact that we have several thousand grape varieties means we have this fantastic genetic resource to draw upon,” says Kym Anderson, emeritus professor at the University of Adelaide and executive director of its Wine Economics Research Centre. He says that growers in McLaren Vale, in South Australia, are swapping Chardonnay for the lesser-known Fiano, a sun-loving Mediterranean grape – something that would have been unthinkable a decade ago.
But not everyone is on board with the changes. “We have to keep our Bordeaux style,” says winemaker Grégoire Pernot du Breuil. At Château de Puygueraud, where he is managing director, he says their blends are 80 per cent Merlot. “We want to go on making good wine. I don’t see any reason to change. This is my point of view.” He isn’t digging up the vineyard. He plans to wait and see.
Back on the periphery of the VitAdapt vineyard, Van Leeuwen and his team set up for an outdoor going-away party for a researcher returning to China. An impressive collection of wine is laid out, in anticipation of a toast. Van Leeuwen reaches for a crisp Greek white made from Assyrtiko (coincidentally, one of two European Vitis vinifera species known to be naturally resistant to Phylloxera). He holds the glass to his nose, sucks in its contents, and keeps it in his mouth for several seconds before swallowing. What’s not to like about this grape, he asks.
Bordeaux, he says, has exported its varieties and wine-making savoir faire to all parts of the world. Now it may be time to look elsewhere, to other countries where some little-known breed of Vitis vinifera is thriving in relative obscurity, and to borrow from them.
Updated 02.01.20, 10:45 GMT: This article has been updated to correct the description of the grape Rkatsiteli. It is of Georgian origin, not Greek.
This article was originally published by WIRED UK
