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Brief History
Grapevines, like many plant species, exhibit a remarkable capacity to modify their genetic
expression in response to environmental challenges, a phenomenon known as phenotypic
plasticity. However, centuries of human-led clonal propagation have curtailed this natural
adaptability. While clonal selection preserves desired traits, it also renders vines more
susceptible to disease, particularly fungal pathogens such as powdery and downy mildew. In
response, grape breeders have long turned to crossbreeding and hybridization as strategies for
resilience.
Systematic efforts to hybridize grapevines began in earnest during the late 18th century. These
initiatives were largely motivated by a desire to improve yields, enhance climatic adaptability,
and bolster disease resistance. Early pioneers included British agronomist William Speechly and
French viticulturist Louis Bouschet de Bernard, the latter of whom developed Petit Bouschet in
1824.
However, it was the phylloxera epidemic of the 19th century that catalyzed a more intensive and
coordinated global breeding effort. The tiny, sap-sucking insect (Daktulosphaira vitifoliae)
devastated vast tracts of European vineyards. Hermann Jaeger, a Swiss-American viticulturist
based in Missouri, became a central figure in the response. He developed more than 100 new
grape varieties and provided American rootstocks resistant to phylloxera, effectively rescuing
European viticulture. Yet, this solution came with a new problem: the inadvertent introduction of
North American fungal diseases such as mildew, to which European Vitis vinifera varieties had
no natural defense.
As a result, breeders redirected their focus toward developing disease-resistant cultivars. Early
hybrids such as Vidal blanc and Müller-Thurgau addressed specific regional needs. But a new
wave of breeding aimed to address fungal resistance more comprehensively. These efforts gave
rise to a new category of grapes: PIWI varieties, fungus-resistant cultivars developed through
interspecific hybridization.
Timeline of PIWI Development
• Mid-1800s:
The phylloxera crisis devastates European vineyards, prompting hybridizing
with American Vitis species for resistance.
• Late 1800s–Early 1900s:
o Albert Seibel creates approximately 16,000 hybrid crosses, many based on Jaeger
70, to combat phylloxera. While successful in the vineyard, his varieties were
often lacking in winemaking potential.o Joannes Seyve breeds cold-resistant hybrids such
as Chambourcin and Traminette, which gain popularity in the eastern United
States.
o Eugène Kuhlmann, based in Alsace, develops hybrids with resistance to fungal
diseases and frost, laying important groundwork for future breeding.
• 1950s:
At their peak, hybrids accounted for approximately 32% of all vineyard plantings
in France. However, concerns over wine quality and marketability prompted the Institut
National de l'Origine et de la Qualité (INAO) to intervene. The INAO took control of
hybridization policy, ultimately banning the use of most hybrids in appellation wines due
to perceived inferiority in quality compared to Vitis vinifera.
• 1985:
Swiss geneticist Valentin Blattner begins developing Vitis vinifera-based fungus-
resistant cultivars inspired by his family's earlier work with Kuhlmann hybrids. His
creations include Cabernet Blanc, Cabernet Jura, Sauvignac, Pinotin, and Satin Noir.
• 1994:
The International Organization of Vine and Wine (OIV) adopts the term “Resistant
Variety” instead of “hybrid”, reflecting an effort to distance these cultivars from the
stigma historically associated with non-vinifera grapes.
• 1999:
PIWI International is founded by Pierre Basler to support and promote fungus-
resistant grape varieties. Today, it includes over 500 members across Europe and
internationally.
It is worth noting that while hybrid grape development also progressed in the United States, it
was primarily geared toward enhancing cold hardiness rather than fungal resistance, as
exemplified by varieties suited to regions like Minnesota and the Finger Lakes.
Uses and Current Relevance of PIWI Grapes
The term PIWI derives from the German “Pilzwiderstandsfähige”, meaning “fungus-resistant.”
These varieties were originally conceived to reduce the need for chemical inputs in the vineyard,
particularly copper-based fungicides like the Bordeaux mixture. Though effective, such
treatments accumulate in the soil over time, negatively impacting long-term soil health and
potentially obscuring terroir expression.
PIWI grapes possess natural resistance to common vineyard pathogens such as Plasmopara
viticola (downy mildew) and Uncinula necator (powdery mildew). As a result, they enable a
more sustainable form of viticulture, one that is increasingly important in the face of climate
change, which has intensified disease pressure and raised concerns about the environmental costs
of conventional viticulture.
While their original purpose was disease resistance, PIWI varieties have demonstrated several
additional benefits:
Key Benefits of PIWI Grapes
• Reduced Chemical Inputs
Thanks to their genetic resistance, PIWI vines typically require only 1–2 fungicide
treatments per season, compared to 8–12 for traditional Vitis vinifera. This makes them
ideal for organic, biodynamic, and low-intervention farming models.
• Heat and Sunburn Resilience
Some cultivars exhibit improved tolerance to heat and UV stress, making them
particularly valuable in higher elevation regions with greater sun exposure facing
increasingly volatile weather patterns.
• Cold Climate Viability
PIWI grapes are extending the boundaries of viticulture into cooler regions like Poland,
the Baltic states, Scandinavia, and parts of the United Kingdom—areas once considered
unsuitable due to their short growing seasons and frost risk.
• Soil Health and Terroir Preservation
By minimizing the need for copper-based sprays, PIWIs support healthier soil
ecosystems, which over time can lead to more transparent and expressive wines.
• Lower Carbon Footprint
Fewer tractor passes, reduced chemical use, and more efficient vineyard management all
contribute to decreased greenhouse gas emissions, an increasingly important metric as
producers and appellations pursue sustainability goals.
Current Applications of PIWI Grapes
As interest grows, PIWI varieties are moving beyond experimental plots and into mainstream
production. Their applications today include:
• Varietal Wines
Several producers now bottle varietal wines made entirely from PIWI grapes such
as Solaris, Souvignier Gris, Muscaris, and Cabernet Cortis. These wines are gaining
traction in wine bars, natural wine lists, and sustainability-focused portfolios.
• Blending Components
PIWI cultivars like Roesler are often used to enhance blends, offering structure,
aromatics, or color intensity. This strategy allows winemakers to reduce chemical usage
while maintaining stylistic continuity.
• Appellation Trials and Legal Integration
Traditional regions are slowly warming to the idea. In Champagne, Voltis has been
authorized for up to 10% of the blend under new INAO regulations aimed at climate
resilience.
• Emerging Wine Regions
In countries with colder climates or younger wine industries, such as Poland, Sweden,
Denmark, and the U.K., PIWIs are not only viable they are leading the charge in
establishing a national wine identity.
Advantages of PIWI Varieties
1. Emerging Markets and Consumer Curiosity
The wine industry is witnessing a paradigm shift driven by a younger, more adventurous
generation of consumers who are eager to discover new styles, varieties, and narratives. This
openness is reshaping the global wine market, where tradition no longer solely dictates value. In
this evolving landscape, fungus-resistant varieties present a compelling alternative.
In metropolitan cities like New York, London, and Tokyo where wine culture intersects with
culinary innovation there is growing interest in wines that are not only delicious but also
sustainable and novel. PIWI wines, with their lesser-known origins and environmentally friendly
cultivation, offer producers a rare opportunity to craft a fresh narrative in a saturated market.
Interview Insight:
In a focused tasting session I conducted with sommeliers from both casual and fine dining
establishments in New York City, consensus emerged on PIWI’s potential. Casual venues with
their younger, more flexible clientele were seen as fertile ground for introducing hybrid wines. In
contrast, fine dining settings, where guests often expect benchmark regions and classic varietals,
may require more careful integration. Retail was noted as a significant challenge particularly for
bottles priced over $20 where unfamiliar grape names can hinder impulse purchases. However,
for restaurant programs offering wines under $100, PIWI could become a distinctive and
profitable addition, provided cost pricing allows.
2. Environmental Sustainability and Reduced Chemical Use
Perhaps the most critical advantage of PIWI grapes is their natural resistance to fungal diseases
such as powdery and downy mildew, two of the most significant threats in viticulture worldwide.
This resistance dramatically reduces the need for synthetic fungicides, offering multiple
environmental and health benefits.
A study by the PIWI Rebsortenanbau in Österreich found that PIWI vineyards reduced chemical
treatments by two-thirds than traditional Vitis vinifera. This translates into:
• Substantial reductions in diesel use from fewer tractor passes
• Lower CO₂ emissions and energy consumption
• Decreased soil compaction and erosion
• Less chemical runoff into nearby ecosystems
• Reduced labor and equipment maintenance costs
These advantages support both organic and biodynamic viticulture goals and align with evolving
consumer preferences. According to a 2020 Eurofins sustainability report, 69% of surveyed
consumers were willing to pay more for products with verifiable environmental certifications.
PIWI wines, when framed appropriately, can meet this demand.
3. Cost-Effectiveness and Lower Farming Inputs
Beyond environmental savings, PIWI varieties offer practical economic benefits for growers.
Reduced chemical inputs and fewer field operations make them particularly appealing in regions
with high labor costs or environmental regulations.
Lower input costs (chemicals, fuel, machinery) combined with higher disease resilience lead to:
• Improved gross margins for growers
• Less dependency on seasonal labor
• Fewer vineyard interventions
• Greater consistency in yield and quality during challenging vintages
This cost-effectiveness is especially valuable for small- to mid-sized producers or those in
developing wine regions looking to enter the market with fewer financial barriers.
4. Flexibility and Climate Adaptability
With global warming altering viticultural zones and weather patterns, adaptability is becoming as
important as tradition. Many PIWI grapes are bred not only for disease resistance but also for
tolerance to extreme conditions, be it frost, humidity, or drought.
Certain varieties like Solaris, Bronner, and Souvignier Gris thrive in cooler, wetter climates
where traditional vinifera struggles. This opens opportunities for regions previously dismissed as
unsuitable for viticulture.
Solaris, Pojer e Sandri, Zero Infinito:
At a tasting organized by distributor M.S. Walker in New York, Solaris a white PIWI grape bred
in Germany was showcased through the wine "Zero Infinito" from Pojer e Sandri in Trentino-
Alto Adige. Grown at 900 meters elevation without any chemical or cellar treatments, the wine
underscored how PIWI varieties can not only survive but excel in high-altitude, low-intervention
conditions.
5. Untapped Market Potential
PIWI grapes offer a blank canvas, an opportunity to create new appellation stories untethered
from centuries-old regional typicity. For producers in regions like Southeast Asia, South
America, or parts of North America without strict vinifera traditions, PIWI presents a chance to
lead rather than follow.
These wines can be branded with a focus on environmentalism, innovation, and regional
experimentation. In doing so, producers can cultivate loyal consumer bases without the baggage
of Old World expectations.
6. Affordable Options for Emerging Regions
While gaining international approval from organizations like the OIV can be time-consuming
and expensive, some countries offer more regulatory flexibility. In regions without restrictive
DOC or AOC systems, PIWI varieties can be planted and vinified with fewer bureaucratic
delays. This supports quicker experimentation, faster time-to-market, and agile product
development especially attractive for new producers seeking market entry.
Disadvantages of PIWI Varieties
1. Threat to Regional Identity
Traditional wine regions pride themselves on centuries of terroir-driven typicity, a synergy
between grape variety, soil, and climate. The introduction of hybrid grapes into such landscapes
raises concerns about homogenization and loss of regional identity. Critics argue that PIWI
adoption could dilute the unique expressions that define historic appellations.
This becomes particularly contentious in regions with legal protections for vinifera-only
cultivation. France, for example, has long maintained tight controls on what varieties can be used
in its AOCs, reinforcing both quality standards and identity preservation.
2. Bureaucratic and Financial Barriers
While breeding a fungus-resistant grape may only take a few years, official recognition is
another story. Securing approval from the OIV or national wine authorities can take a decade or
more and cost upwards of €100,000 per variety.
Such barriers limit global scalability and market reach. For many producers, this long and
expensive process is a deterrent particularly when the market for PIWI is still maturing.
3. High Upfront Investment and Risk
Swapping out established vinifera vines for PIWI alternatives involves significant risk. These
include:
• Loss of brand equity tied to classic grapes like Cabernet Sauvignon, Chardonnay, or
Pinot Noir
• Limited consumer recognition and trust
• Lower initial yields in some cases
• Uncertain return on investment
For premium producers or those with long-established client bases, this leap into the unknown
may seem too risky without guaranteed rewards.
4. Uncertain Long-Term Performance
PIWI varieties are relatively young in viticultural terms. Their long-term performance across
various terroirs is not yet fully understood. Concerns include:
• Aging potential of wines made from PIWI grapes
• Consistency across vintages and growing regions
• Compatibility with complex soils and microclimates
This lack of historical precedent makes producers, especially those invested in high-end wines
cautious. Until more data and benchmark wines exist, PIWI’s place in fine wine remains
debated.
5. Limited Market Recognition
Consumer familiarity still leans heavily toward known grape names. Grapes like Cabernet,
Merlot, and Sauvignon Blanc dominate retail shelves and wine lists because they signal
reliability. PIWI varieties, many with unrecognizable names like Johanniter or Cabertin lack this
built-in trust.
Even if the wine inside is high quality, unfamiliar labeling can act as a psychological barrier.
Sommeliers and wine educators will play a critical role in bridging this gap.
6. Premium Price Point
Ironically, despite their sustainability narrative, many PIWI wines are currently sold at a
premium often above $30. This is due to limited production, novelty, and the costs of small-
scale, manual farming.
For everyday wine drinkers seeking affordability, these price points can be prohibitive. Mass-
market success will require a balance between innovation and accessibility.
OPINION: Rethinking the Role of PIWI in the Future of Wine
For centuries, Vitis vinifera has been revered as the cornerstone of fine winemaking. It is the
grape species that underpins the world’s most iconic wines, from Bordeaux to Barolo, Burgundy
to Barossa. This veneration has shaped a mindset across the global wine industry:
that vinifera equals authenticity, tradition, and quality. As a result, other species and hybrids
have often been regarded with skepticism, dismissed as inferior or lacking in finesse.
However, as viticulture faces mounting environmental and economic challenges, we must
question whether this unwavering devotion to vinifera is sustainable or even
logical. Hybridization, particularly with fungus-resistant varieties like PIWI offers practical
solutions to some of the most pressing issues of our time: climate change, fungal pressure,
chemical dependency, and agricultural resilience.
The Sensory Stigma: Real or Perceived?
Critics of hybrid grapes often cite unfavorable sensory traits. Some hybrids are known to
exhibit thicker pectins, potentially affecting mouthfeel or juice yield. Others carry aromatic
compounds such as methyl anthranilate, which can contribute to the "foxy" or grapey notes
commonly associated with Vitis labrusca, like Concord. These traits have historically cast a
shadow over the category, reinforcing a narrative that hybrids are technically useful but
organoleptically flawed.
Yet such generalizations are increasingly outdated. PIWI varieties, many of which are more than
85% vinifera in their genetic makeup have significantly improved over the past two decades.
Breeders now prioritize quality alongside resilience, and today’s PIWI grapes are capable of
producing wines with elegance, complexity, and typicity.
A Market in Transition
From a business perspective, the association of PIWI with "non-traditional" or "experimental"
winemaking can pose a marketing challenge. But as with any trend, consumer preferences
evolve. What is niche today may well become the norm tomorrow.
Younger wine drinkers, in particular those shaped by environmental awareness, authenticity, and
curiosity are increasingly open to alternative narratives. In urban centers like New York, London,
and Copenhagen, there is a rising appetite for sustainable wines with unique stories, even if the
grapes are unfamiliar. This shifting landscape creates fertile ground for PIWI varieties, if
positioned thoughtfully.
Education as the Turning Point
Despite these opportunities, awareness remains critically low. During a personal search for PIWI
wines in New York, I found only one wine shop in Brooklyn where the staff had even heard of
them. Even within the sommelier community, the term "PIWI" often draws blank stares or is
misunderstood.
This lack of awareness is exacerbated by confusion in educational materials. Some sources
mistakenly classify PIWI grapes as GMOs, while others oversimplify them as hybrids without
context. The reality is more nuanced: PIWI varieties are typically the result of conventional
crossbreeding and often retain a majority vinifera genome. These misconceptions create
unnecessary resistance among both consumers and professionals.
Addressing this requires a unified effort in education and storytelling. We must present PIWI not
as a compromise, but as a next step part of a broader conversation about responsible agriculture
and adaptation.
A Blind Tasting Experiment
To test prevailing assumptions, I organized a blind tasting with New York sommeliers,
comparing four PIWI wines to two classic vinifera benchmarks:
• Muscaris 2022, Josef Totter, Vulkanland Styria, Austria
• Sauvignac 2022, Kobatl “Rumble in the Jungle,” Styria, Austria
• Roesler 2021, Schrammel 2.0 “Alternativwein,” Weinviertel, Austria
• Cabernet Cortis 2023, Petit Sauvage, Vin de France
• California Chardonnay
• Sicilian Nero d’Avola
The results were telling. Most participants struggled to distinguish the vinifera selections from
the PIWI wines. This underscores a key point: the sensory gap is far narrower than assumed.
When stripped of labels and biases, PIWI wines can stand confidently on their own merit.
Coexistence, Not Replacement
It would be reductive to frame PIWI as a threat to vinifera. Rather, the two can coexist,
complementing each other across different regions, climates, and market tiers. In cool or humid
regions, where fungal pressure is relentless, PIWI may offer more consistent yields with fewer
interventions. In drier areas or for iconic terroirs, vinifera will likely continue to reign.
The essential question becomes: Are we willing to gamble with increasingly
volatile vinifera harvests, or should we hedge our bets with resilient alternatives? For growers,
it’s a question of viability. For consumers, the focus remains on flavor, value, and experience.
The Power of Language and Framing
Another critical issue is language. The term “Pilzwiderstandsfähige” is cumbersome and opaque.
Even “PIWI” lacks resonance outside specialist circles. “Hybrid” may be easier to digest, though
it, too, carries baggage. We must find accessible, compelling ways to describe these grapes, ways
that emphasize benefits rather than breeding history.
Terms like eco-friendly, low-intervention, resilient, or climate-smart might be more persuasive
than “fungal resistance.” Likewise, highlighting low carbon footprints, reduced pesticide use,
and organic compatibility appeals directly to the values of the modern wine consumer.
Regulatory and Scientific Realities
It’s worth noting that PIWI is finding greater acceptance in Old World regions a counterintuitive
twist, given the traditionalism often associated with these areas. Today, over 130 PIWI varieties
are permitted in Europe, particularly in Austria, Germany, Switzerland, the UK, and
Scandinavian countries. The reason is simple: fungal pressure is a constant threat, and PIWI
vines require significantly fewer chemical treatments.
In contrast, New World adoption has lagged, possibly due to a combination of lower disease
pressure in some areas, regulatory inertia, and market conservatism. Additionally, pathogen
evolution remains a concern. Just as in conventional agriculture, today’s resistant cultivar may
become tomorrow’s liability if breeding and monitoring do not keep pace.
Regulatory questions also remain. At what point does hybridization challenge cultural heritage or
face opposition from appellation authorities? These are not just legal debates they’re existential
questions for regions that define themselves through tradition.
Conclusion: The Story We Tell
The future of PIWI isn’t simply about the grape it’s about the story we choose to tell. As wine
professionals, we have a responsibility to expand the narrative beyond “vinifera or bust.” This
means embracing complexity, questioning orthodoxy, and being open to innovation without
abandoning respect for heritage.
PIWI varieties represent more than disease resistance. They symbolize a shift toward sustainable
viticulture, a response to ecological necessity, and a test of our ability to adapt as stewards of the
wine world. If we frame them as tools for environmental stewardship and expressive
winemaking, not as technical outliers, we may find that the market is far more receptive than we
think.
Ultimately, it is not the grapes that will determine PIWI’s future. It is us.
