Autor: Darcy O’Neil  –

There are always risks when growing grapes in Canada. The winter of 2021/22 was brutal in the Niagara region, not just because of the cold temperatures (-26°C in some places) but extended wet periods in the fall, which resulted in upwards of 50% crop loss for 2022 and long-term damage to a significant number of vines. Getting some vineyards back into full production may take 3 to 5 years. Miserable winters are an accepted risk amongst Canadian grape growers. However, from crisis comes opportunity.

When upwards of 50% of a vine-growing region suffers severe damage, it opens the possibility of reassessing the direction winemakers will take in the future. A genuine opportunity for this region may come with planting the modern European PIWI varieties developed at breeding programs in Germany at the Julius Kuhn Institute, Freiburg University and France’s INRA (Institut National de la Recherche Agronomique). France has invested in developing hybrids, because of global warming and for sustainability reasons. Germany has excellent breeding programs that produce vines that are 80% to 90% vinifera. The German government considers these vines Vitis vinifera because they contain only a tiny percentage of non-vinifera species. If Europe is embracing PIWI grapes, then maybe Canada should embrace the benefits of modern PIWI grapevines. The benefits of planting PIWI grapes are significant, and the wine quality is on par with current vinifera varieties.

Global warming has shown that the weather will get more extreme in the coming years. For Ontario, that means a wetter, more humid growing season. And, by extension, more disease pressure from fungus.

The current rate of fungicide use is unsustainable, and there will inevitably be acquired resistance to the current fungicides. Furthermore, the evolution of fungi will always outpace the ability of chemists to develop new fungicides. And if you have noticed fuel prices recently, driving a tractor through a vineyard 8 to 12 times per year to spray fungicide can be costly. PIWI grapes offer an economical solution to both issues.

Hybrid grapes are well known in Canada, so they are already accepted. Vidal, a cross of Ungi Blanc and Rayon d’Or (Seibel 4986) mainly used to produce ice wine, represents the highest grape yield in Ontario, with an annual output of 21000 tons. Riesling comes in second at 10700 tons annually. Hybrid grapes account for 38% of the total grape yield in Ontario, with Baco Noir (3750 tons) being a popular red variety and older European hybrids, like Seyval Blanc and Chambourcin (1500 tons) making contributions. Though varieties like Vidal and Baco Noir exhibit some resistance to powdery mildew (Oidium), they are susceptible to downy mildew (Peronospora) and other fungi.

A growing number of vineyards are planting University of Minnesota hybrids (e.g. Marquette, Frontenac). Though these varieties are primarily bred for cold resistance, their extensive use of Riparia and Labrusca in their breeding program does provide fungal resistance. However, they also create some distinct hybrid notes, which can affect the acceptance of wines made with these grapes into the Vintners Quality Alliance (VQA) and limit the export to other countries with appellation systems (AOC, DO, DOC, QmP).

Cold Temperature Performance for New Hybrids?

Many of these PIWI vines have only been released in the last 20 years, but there is already good research on cold hardiness. For example, a research paper from Poland (Cold Hardiness of Primary Buds of Wine and Table Grape Cultivars in Poland J. Lisek*, A. Lisek (2020)) rates most PIWI grapes as more cold tolerant than Merlot and similar to Riesling, but not as hardy as the Minnesota hybrid grapes. The Italian varieties from Università Degli Studi di Udine claim cold tolerance down to -23°C for most of their vines. Though modern PIWI grapes are primarily bred for flavour and disease resistance, the use of other Vitis species does give them a cold hardiness advantage over Vitis Vinifera.


PIWI grapes from the French, German and Italian breeding programs are now available to Canadian grape growers, though some varieties need to be imported from the United States.

French (IRNA) PIWI Varieties

Currently available in Ontario through Vinetech.

Artaban and Vidoc (red) are:

  • A collaboration between JKI and INRA.
  • They are a cross of Regent (Chambourcin X Diana (Silvaner x Müller-Thurgau)) with a complex French hybrid (VRH3082-1-42) that includes Cabernet Sauvignon and Merlot Noir.
  • Auban, a vinifera grape that has some resistance to downy and powdery mildew, is a grandparent (25%).
  • Vitis rotundifolia (muscadine) is an initial parent to provide the fungus resistance genetics.

Floreal and Voltis (white)

  • a cross between Villaris (Vidal Blanc x Sirius (Bacchus x Villard Blanc)) from JKI in Germany and a complex French hybrid (VRH3159-2-12) from INRA
  • Vidal is a grandparent (25%) of these two varieti


  • The cross includes Chasan (Palomino Fino x Pinot), Semillon, Garnacha, and Cabernet Sauvignon.
  • The fungus resistance comes from Vitis rotundifolia (muscadine) being an initial parent in the breeding program.

The JKI variety Regent (R) (Chambourcin X Diana (Vinifera)) is available through Vinetech as well but in limited quantities (currently sold out for 2023).

Italian PIWI Varieties

The Italian varieties are available through Novavine in California. These vines use a complex hybrid from Hungary (Kozma 20-3) that includes Vitis Amurensis Ruprecht and Vitis Rupestris (from Villard Blanc) for disease-resistant genetics while combining multiple Vitis vinifera including Afus Ali, Traminer, Pinot and Muscat in its lineage. These Italian hybrids exhibit excellent cold hardiness, with reported tolerance to -23°C (Merlot Kanthus is good too -20°C), which is similar to Riesling.

Cabernet Volos (R) – Cabernet Sauvignon X Kozma 20-3

Fleurtai (W) – Tocai Friulano x Kozma Kozma 20-3

Merlot Kanthus (R) (Merlot X Kozma 20-3)

Sauvignon Kretos (W) (Sauvignon X Kozma 20-3)

Sauvignon Rytos (W) (Sauvignon x Bianca)

Soreli (W) – Tocai Friulano X Kozma 20-3

Minimum order of 1000 vines is required for shipping to Canada.

Novavine Hybrid Grapes Handout

JKI (Germany) PIWI Varieties

Licensing and importing PIWI varieties from JKI in Germany is currently underway, and vines should be available in a few years.

These hybrid vines use Vidal and Seyval Blanc in their breeding progra

m. Villaris looks like an excellent grape for ice wine production, and Felicia, a sister grape to Villaris, both have Vidal as a primary parent (50%).

Villaris (W) – Vidal Blanc x Sirius (Bacchus x Villard Blanc)

Felicia (W) – Vidal Blanc x Sirius (Bacchus x Villard Blanc)

Calandro (R) – Domina x Regent

Calardis Blanc (W) – Calardis Musque x Seyve Villard 39-639

Calardis Musque (W) – Bacchus x Seyval

Freiburg (Germany) PIWI Varieties

The University of Freiburg PIWI varieties can now be exported from New

York state through Amberg Grapevines.

The Freiburg varieties use Merzling (Seyval Blanc x (Riesling x Pinot Gris)) as a primary breeding partner in many of their crosses, either directly or through Solaris and Bronner. The currently available vines at Amberg are:

Helois (Merzling x (Seyve-Villard 12-481 x Müller-Thurgau))

Johanniter (Riesling x (Seyve Villard 12-481 x (Pinot Gris x Gutedel)))

Muscaris (Solaris x Muscat Blanc)

Monarch (Solaris x Dornfelder)

Eric Amberg is currently looking at importing other varieties, so if you have a preference, please get in touch with Amberg directly to let them know which vines you are interested in. The following Freiburg varieties rate high in the PIWI Wine Awards.

Carbernet Carbon (Cabernet Sauvignon x Bronner)

Cabernet Cortis (Cabernet Sauvignon x Solaris)

Souvignier Gris (Seyval Blanc x Zähringer)

Prior – ((Joan Seyve 234-16 x Pinot Noir) x Bronner)

Solaris – (Merzling x Gm 6493)

Bronner (Merzling x Gm 6494)

There are additional breeding programs in Switzerland, Austria, Hungary and the Czech Republic but importing grapes into Canada/North America is lengthy and challenging. The INRA in France is currently approved, and the process for G

ermany is underway. Because the growing season in Canada is similar to Germany and France, it makes sense to start here.

The benefits of planting PIWI grapes in Canada are many. They are more environmentally friendly and sustainable while being more economical by reducing vineyard inputs like fuel, fungicides, labour and wear-and-tear on tractors. The wines are similar to vinifera and, in some cases, indistinguishable. PIWI grapes offer the oenophile a great tasting, sustainable wine, while vignerons get a more financially friendly vineyard. What’s not to like?

If you have questions, please get in touch with Darcy O’Neil or PIWI International because we are here to help.

Darcy S. O’Neil is currently the coordinator for the Canadian PIWI regional group. He has written about drinks, cocktails, soda and wine for 18 years but originally studied chemistry and has worked in research labs for 15. Darcy and his wife, Dr. Anna Mayer, are planting 4 hectares of PIWI grapevines in Ontario.


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