PIWI varietals are a group of grape varieties specifically bred to be resistant to fungal diseases such as powdery mildew and downy mildew. The term "PIWI" is derived from the German phrase "Pilzwiderstandsfähig," meaning "fungus-resistant."

These varietals are developed through traditional crossbreeding techniques, often involving European Vitis vinifera and other species like Vitis labrusca, Vitis riparia, or Vitis amurensis, which naturally exhibit higher resistance to fungal diseases.

Several PIWI varietals are gaining popularity and recognition in the wine world:

Regent - A red grape variety known for its deep color, good tannin structure, and resistance to both powdery and downy mildew. It produces wines with flavors of cherry, plum, and blackberry. Read more here. 

Solaris - A white grape variety notable for its early ripening and high sugar content, making it suitable for cooler climates. It produces wines with tropical fruit flavors such as pineapple and mango. Read more about Solaris here. 

Phoenix - Another white grape variety resistant to fungal diseases. It produces aromatic wines with flavors of elderflower, citrus, and sometimes honey.

Johanniter - A white grape variety resistant to downy mildew and other fungal diseases. It produces wines with a balance of acidity and fruitiness, often with notes of apple and pear.

Rondo - A red grape variety resistant to mildew that produces wines with deep color and berry-like flavors.

PIWI varietals are playing an increasingly important role in modern viticulture for several reasons:

Sustainability - Due to their resistance to fungal diseases, PIWI varietals require significantly fewer chemical treatments (such as fungicides). This contributes to more sustainable and environmentally friendly viticulture practices.

Cost-Effectiveness - Reduced need for chemical treatments lowers vineyard management costs, making grape production more economically viable, especially in regions where fungal diseases are prevalent.

Adaptation to Climate Change - As climate change impacts traditional wine-growing regions, PIWI varietals offer a resilient alternative that can thrive in more challenging growing conditions.

Expansion of Wine Regions - PIWI varietals enable wine production in regions previously unsuitable due to high humidity and disease pressure, thus expanding the geographic footprint of viticulture.

Consumer Awareness - With growing consumer awareness and demand for sustainable and organic products, PIWI wines offer a marketable attribute for producers aiming to meet these preferences.

Overall, PIWI varietals represent a significant innovation in viticulture, offering solutions to some of the pressing challenges faced by the wine industry today. Their continued development and adoption are likely to shape the future of wine production, emphasizing sustainability, resilience, and adaptability.

Wine Countries Where PIWI Varietals Play a Special Role

Denmark - A low average temperature, much rainfall, and a low amount of sunshine force Danish winemakers to focus nearly exclusively on growing PIWI varietals. See more in our article on Danish wine.

Sweden

Switzerland

Poland

Canada

Further Readings

PIWI International