Are Hybrid and PiWi Grapes Climate Saviors?
Photography by Tom Arena /. THE WINE ENTHUSIAST
Last year, I blind tasted two wines with a group of wine friends in Austria: a Welschriesling and a Souvignier Gris from the same producer. Both were delightful, but the Souvignier Gris, a hybrid grape (or, in Europe, PiWi), won the crowd. When its PiWi origins were revealed, the room erupted in disbelief. “Wait, a hybrid?”
That moment was a reminder: Wine isn’t just about tradition or labels. It’s about reinvention, resilience and the bold wines that challenge the status quo—especially those that could offer a more sustainable
future. The wine world is full of biases and misconceptions, and it’s easy to fall into the trap of thinking we know what’s worth our time. But knowledge, like any good drink, can numb the senses. Without labels, the truth is in the glass.
Hybrid grapes are a growing topic of debate in the wine world. While some still view them as a passing trend, others believe they may hold the key to a more sustainable and resilient future in viticulture.
Wine, as we recognize it today, has existed for at least 8,000 years. Along the way, viticulture has been shaped by history, culture, climate and the land itself. Vines haven’t just been cultivated, they’ve been carried along by migrations, swept by wars and the whims of empires. Over centuries, they’ve been spread, grafted and crossed.
Among the many species of grapevines, Vitis vinifera emerged as the dominant variety, responsible for the majority of our most popular grapes, like Cabernet Sauvignon and Chardonnay. Christian monks in the Middle Ages who studied and realized the potential of certain varieties for quality, chose certain grapes and left others behind. But it wasn’t just monks that narrowed down the selection. By the late 1800s, phylloxera, the devilish root louse that decimated Europe’s vineyards, a natural disaster that gave the industry a fresh start, of sorts.
The survivors were the tried-and-true. And when those vines were replanted, they stuck to what worked. Big names, familiar names, marketable names. This is how in Burgundy, for instance, we came down to only a few varieties, despite the fact that many French grapes originated there.
Fast forward a century, and we’re left with a lack of diversity. “Wine is one of the worst monocultures,” says Luisa Slotwinsky, assistant winemaker to Alto Adige’s Thomas Niedermayr, one of the wineries that has committed entirely to PiWi grapes.
This resulted in weaker vines vulnerable to disease and climate shifts, often requiring chemical treatment.
“They’re useless without spraying,” says Didier Grappe of Domaine Didier Grappein Jura, who also organizes Résistance, a wine fair dedicated exclusively to hybrids. “It feels much better to grow grapes in a clean [hybrid] vineyard, than an oversprayed [vinifera] vineyard.”
Yet, before we began cultivating vines for wine, nature had already crossed species, creating wild hybrids resistant to frost, disease and drought. These native vines, the rebels of the vine world, are the product of nature’s survival instincts, offering a key to resilience in a changing world.
Keeping Up with Climate Change
The climate is changing faster than wine itself. You are almost guaranteed that surprising insights will lead the way to the future—like stepping away from market trends and focusing on a more sustainable future by embracing hybrid varieties, as many growers around the globe are doing.
One such grower is Deirdre Heekin, proprietor and winemaker at Domaine La Garagista in Vermont, which she runs with her partner, Caleb Barber. During my visit, Heekin showed me a wild vine that had climbed nearly 30 feet up a tree, reaching for sunlight.
“These are lianas,” Heekin explains, pointing out the plant’s resilience and offering a glimpse into the untamed roots of grapevines. Heekin reminds me that it was exactly these varieties that saved the European wine industry. In the late 19th century, after phylloxera ravaged vineyards across Europe, scientists discovered that European vinifera vines could be grafted onto native, phylloxera-resistant rootstocks from North America, which carried the louse to Europe in the first place.
This created a lifeline between Old World wine culture and the new world of American viticulture. Reliance on early, imperfect forms of pesticides like Paris Green and carbon disulfide wasn’t an option at the time, and the simple rootstock of native vines proved to be the solution.
However, this wasn’t the only nuisance that arrived in Europe from North America, affecting vinifera. Powdery mildew, or Oidium tuckeri, wreaked widespread havoc. Identified in London in 1845, this fungal disease wasted no time spreading, targeting key wine regions with bustling coastal trade routes, such as Madeira, Bordeaux and Porto.
Powdery mildew is the quiet assassin of the vineyard, thriving in the damp, humid corners with little sunlight. It doesn’t just nibble at the edges; it suffocates the life out of a vine, preying on the plant’s leaves, shoots and grape clusters. By the mid-19th century, it was on a rampage, slashing through Europe’s vineyards with the precision of a scythe. In France, production was gutted, collapsing to a quarter of what it once was.
The Evolution of PiWi
Then, downy mildew marched in, riding in with the very American native vines brought to fight the first two plagues. A fungal opportunist, it thrives in the same humid heat, leaving oily yellow blotches on leaf tops and ghostly white mold below. It damages vital organs, like buds and blossoms. It wasn’t just a setback; it was a siege, leaving growers scrambling to salvage what little remained.
The wine industry launched a determined quest to combat these devastating threats, driven by necessity and a refusal to let its traditions be toppled.
“Since the mid-19th century, nobody was able to practice viticulture as before. We all have to use rootstocks, copper and sulfur,” says Valentin Morel, proprietor of Les Pieds sur Terre winery in the French Jura.
For years, this strategy worked—sort of. Then the chemical industry stepped in, offering up a new arsenal of fungicides to battle mildew. In damp, humid regions, spraying became relentless, an endless cycle through the growing season.
This remains the reality today. Organic growers stick to the basics: copper and sulfur. They’re safer, but they only coat the surface, washing away after a good rain. Conventional growers use systemic fungicides that penetrate the foliage, lasting longer but with potential downsides. Overuse can lead to resistance, turning yesterday’s solution into tomorrow’s problem. And while generally effective, large-scale use of these chemicals comes with environmental and health risks that can’t be ignored.
In response to the challenges at the end of the 19th century, hybrid breeding gained momentum in France led by trailblazers like Georges Couderc, Eugène Kuhlmann, Albert Seibel and Bertille Seyve. According to Wolfgang Renner, chairman of PiWi Austria and a viticulture researcher at the Haidegg Experimental Station for Fruit Growing & Viticulture, these pioneers laid the groundwork for a new era in grape cultivation. Their efforts combined innovation with practicality, aiming to create vines that were not only resilient but also capable of producing wines worth drinking.
“The first goal was the fight against phylloxera,” explains Renner. Crossbreeding for resistance to fungal diseases came a bit later. “By the mid-20th century, we [had moved into] modern resistance breeding.” The early success of hybrids like Léon Millot, Seyval Blanc and Villard was enormous.
“In France in 1958, almost 40% of the total vineyard area were hybrids,” says Morel, who also wrote a book titled Another Wine which talks about hybrids. But the French government wasn’t having it. Hybrids were seen as a stain on France’s image as the land of fine wines. So, in 1979, they passed a law forcing the removal of hybrids from the vineyards.
Research and breeding didn’t stop after France shut the door on hybrids. Innovation thrived in German speaking countries, where cool, damp climates presented constant challenges for Vitis vinifera. Enter PiWi grapes, shorthand for Pilzwiderstandsfähige Rebsorten—a tongue-twister that translates to fungus-resistant grape varieties. These vines are precision-bred to fend off relentless fungal foes like downy and powdery mildew.
Valentin Blattner, a Swiss-born geneticist, grape breeder and winemaker, has done a great job finding varieties that work both in the field and the glass. Among his most successful new crossings are Cabernet Blanc, Pinotin, Satin Noir and Cabernet Jura.
PiWi varieties achieve their resistance by incorporating genes from naturally resistant species such as Vitis labrusca, Vitis amurensis, Vitis rotundifolia and Vitis rupestris. These species have evolved to thrive in harsh conditions. The more resistance genes that are introduced through crossbreeding, the more durable and long-lasting the vine’s ability to withstand these threats becomes.
“All the varieties of Valentin Blattner are really promising—we just have to be wary about their possible future sensibility because they have a big part of vinifera genes,” says Valentin Morel.
Wolfgang Renner says that the goal in modern resistance breeding is the transfer of several resistance genes over several breeding steps.
“Monogenic resistant varieties can lose their resistance, [so] in the next few years we will find new varieties with three resistance genes against downy mildew, three resistance genes for powdery mildew and one gene for black rot. These varieties are going to be pretty strong,” he claims.
The new PiWi vines are not just frost-resistant; they’re also better equipped to handle the unpredictable, shifting weather patterns brought on by climate change. With a shorter growing season, PiWis often avoid late frosts, making them ideal for the increasingly erratic weather that modern winegrowing faces.
Look back to the comparison of Welschriesling and Souvignier Gris. The winemaker behind these wines is Franz Weninger, from his namesake winery in Austria’s Burgenland. While Weninger remains somewhat skeptical that hybrids can achieve the same heights as vinifera, he acknowledges their growing advantages in the vineyard.
“Without much effort, this Souvignier Gris had a lower pH than any other white I made this year,” he notes. “It retains acidity, and I barely had to spray it to get a good yield.”
Rewriting the Script
On paper, the recipe for hybrid vines seems straightforward: Start with a sturdy American rootstock, toss in some frost-resistant Asian genetics, and finish with a touch of European vinifera elegance. The idea is to create a vine tough enough for the vineyard yet refined enough for the glass. But winemaking, like nature, rarely follows a script.
“Breeding is constantly trying to adapt, but is unfortunately often one step behind,” explains Wolfgang Renner. “The whole process can take up to 15 to 20 years until commercial propagation.”
The creation of a PiWi variety is a meticulous process that combines science, patience and a touch of artistry. It begins with a clear goal: breeding a vine that can resist a certain climatic challenge. The first step is selecting the parent varieties, combining the toughness of resistant species with the finesse of vinifera through classical crossbreeding. From this pairing, seedlings are cultivated and undergo rigorous observation to assess their resistance behavior.
DNA analysis plays a key role in identifying specific resistance markers to narrow down the most promising candidates. These selected vines then face outdoor testing to evaluate their performance in real-world conditions. Once they pass this stage, wine is produced from the grapes, with sensory analysis determining if the flavor profile meets quality standards. Only after clearing these hurdles can the variety proceed to admission, authorization and eventually propagation.
My first real encounter with a PiWi-focused winery came while visiting Ploder-Rosenberg in Austria’s Styria, one of Europe’s rainiest regions. Fighting fungal diseases here is a constant battle. The turning point for the Ploder family came in the early 2000s when they transitioned to biodynamic farming. Alfred Ploder realized that adopting more resistant varieties would make this shift easier. Nearly 20 years later, PiWi varieties now make up 80% of their 11 hectares.
However, a leader in this part of the world is Rudi Niedermayr, the father of Thomas Niedermayr. Rudi shifted from conventional farming after observing the deterioration of the soils, but the demands of the environment were not well suited to organic farming.
He pivoted to cultivating mildew-resistant PiWi varieties, which enabled pesticide-free viticulture and improved soil health. He was the first to plant varieties, like Solaris, Bronner and Souvignier Gris in Italy. With this change, he was able to reduce the need for tractor movement, lower CO2 emissions and promote better soil aeration, water retention and biodiversity. Rudi’s dedication led him to start breeding his own resistant varieties by 2005.
“These grow from seedling to vine in our mother garden on the farm,” says Luisa Slotwinsky. “This results in grape varieties that are adapted to our soils and the special microclimate on the farm.”
Many other growers I’ve met who work with PiWis talk about how little they have to spray them, if at all, and many of them are convinced that this is the only future of sustainable viticulture. Wolfgang Renner confirms their experience with a real study he did a few years ago.
“Compared to traditional grape varieties, I found a reduction in applications against fungal diseases of up to 80%,” Renner says. “This in turn means significantly fewer pesticides, lower CO2 emissions and, of course, lower costs.”
It is exactly this observation that led Thomas Niedermayr to focus his entire production of PiWi grapes in 2019.
Bring It All Back Home
One of the biggest hurdles hybrid varieties face is the name itself. “We don’t speak about hybrids anymore, they are the old generation of breedings,” says Wolfgang Renner. This is how the abbreviation PiWi came into wider use in Europe.
Renner acknowledges that discussions about the quality of PiWi wines can be controversial. However, the number of wineries exploring these varieties continues to grow, with some even expressing genuine enthusiasm. The bigger challenge, he notes, lies in convincing consumers.
“People often ask me about hybrids,” says Valentin Morel, who gets questions about if these “engineered” grapes can transmit a sense of place. “I understand the question, but it’s also ethically problematic because it shows a cognitive bias. No one asks, ‘Is a Chardonnay sprayed 20 times with pesticides still a terroir wine?’ That said, I’ll answer. For me, yes, hybrid varieties can express terroir, especially the whites I’ve experimented with. They can express terroir just like vinifera, provided the winemaker does a good job in the vineyard, keeps yields low, and respects the grape during vinification, with a relatively long élevage.”
Deirdre Heekin of La Garagista in Vermont initially planned to work with vinifera varieties like Riesling and Blaufränkisch, which thrive in cool climates. “They failed miserably,” she says. “But then I realized that I don’t need them. Many people make good Riesling or Blaufränkisch, but who makes a good
Marquette?”
Her work has inspired a community of Vermont growers using hybrids such as La Crescent, Marquette, Frontenac Gris, Frontenac Blanc, Frontenac Noir, Brianna and St. Croix. Heekin explains that good farming and low-intervention winemakingare key to producing quality wines from these varieties.
Matthew Niess, winemaker and proprietor of North American Press winery in California, explains his commitment to working with hybrid grapes like Baco Noir. His initial inspiration came from a desire
to craft a distinctly American wine.
Niess points out that hybrids are not a uniform category. Each has its own characteristics, with some more vigorous than vinifera, but they generally require fewer pesticides. This disease resistance aligns with his regenerative farming practices, which aim to reduce fungicide use, minimize irrigation and support biodiversity. “It’s the essence of regenerative agriculture: a self-sustaining cycle,” he says.
He also emphasizes how hybrids fit into California’s climate challenges, especially regarding drought and heat. Varieties like Lenoir thrive in these conditions and resist diseases like Pierce’s disease, which
is increasing in the region.
While the wine industry remains skeptical about hybrids, Niess is optimistic. “Younger wine consumers are less concerned with ‘noble’ varieties,” he says, noting their interest in new flavors and the fact that hybrids address environmental, social and economic sustainability. Despite industry resistance, Niess sees the growing appeal of hybrid wines, with positive feedback from both critics and consumers.