By Jerry Kolins, Diploma Candidate, WSET
Before I explain PIWI, please permit a short digression of my two favorite options for wine education, i.e., The Court of Master Sommeliers (CMS) and the London-based Wine and Spirit Educational Trust (WSET).
CMS focuses on service, and its leaders are second to none. At a par with CMS's education is the WSET. WSET’s purpose “is to empower people through inspiring learning experiences worldwide.” WSET provides qualifications for wines, spirits, sake, and beer. The diploma that I seek from WSET is a prerequisite for entry into the coveted Master of Wine (MW), which has been awarded a little more than 500 times.
To achieve a diploma from WSET, six modules must be completed, including Wine Production (D1), Wine Business (D2), Wines of the World (D3), Sparkling Wines (D4), Fortified Wines (D5), and an independent research assignment (D6). It was in the sixth module (D6) that I discovered PIWI.
PIWI (pronounced pee-vee) is an abbreviation for the German word Pilzwiderstandsfähige. Because the word Pilzwiderstandsfähige is almost impossible to pronounce, PIWI indicates “specially bred fungus-resistance grape varieties with at least 85% Vitis vinifera in their genomes.[1]
Why breed hybrid varietals of the spectacular Vitis Vinifera? The answer to this question includes consumer health concerns, climate change, and the desire to avoid poisons.
Consumers are drinking more “alcohol-free” wines and wines from organically grown grapes in the hopes of protecting the environment and themselves. Not well appreciated is the need to protect almost all Vitis Vinifera vines from downy mildew, a fungus that affects the vine, including the grapes, resulting in a loss of fruity flavors and a moldy bitter taste. Crop loss reached 70% in France during the wet weather of 1915.[2] The treatment is a concoction of copper.
Copper is a heavy metal that does not degrade in soils. In an interview with Master Sommelier David Keck of Stella 14 Vineyards in Vermont, David comments that it is extremely difficult, if not impossible, to eliminate copper completely from the vineyard. Master of Wine Joshua Grainer of RdV Vineyards in Virginia agrees.
The solution to eliminate poisonous heavy metals from the soil is to breed mildew-resistant vines. This has been accomplished. However, it should be noted that 100% resistance to downy and powdery mildew has not yet been achieved. However, the reduction in soil pollution with heavy metals is estimated at 80% compared to organically grown vines. Surprisingly, organic vineyards use twice as many fungicides as conventionally grown vineyards since their fungicides are less potent.[3]
Hybrid wines with 85% Vitis Vinifera DNA are called PIWI wines, not hybrids, because most of us think of a hybrid as inferior to any wine made from Vitis Vinifera. The Champagne region of France disagrees. The French have made progress in protecting the environment from copper with a breeding project called ResDur (Resistance Durable). It is difficult to believe, but the French now permit a new resistant PIWI variety, Voltis, in their Champagne! But it cannot be more than 10% of the blend. With climate change, the Voltis variety retains acidity better than Chardonnay and has a later budburst, which may provide some protection from spring frost.[4]
So, what do PIWI wines taste like? As my attachment shows, they are obtainable in Europe. But I have not found these wines readily available in the USA. Breeding in the USA occurs at Cornell, Minnesota, and Michigan and includes Cayuga, Marquette, and various Frontenacs. Perhaps it is time for a comparative wine tasting, i.e., PIWI wines vs. Vitis Vinifera. In Davidson, NC, Vine Society may be the perfect location for this comparison.
[1] Goode, J, (2022) Regenerative Viticulture, Independently Published, p144
[2] Ibid, p113.
[4] Ibid, p155
