PIWIs, acronym for pilzwiderstandsfähige Sorten, a German-language term for hybrid grape varieties or interspecific crossings bred for their resistance to fungal disease organisms

According to Dr Rudi Eibach ‘the European Union banned hybrids or interspecific crossings for use in quality wine [meaning AOC/AOP or IGT/IGP wines] because generally speaking the older examples, like Seibel and Seyve Villard, could not compete qualitatively with Vitis vinifera varieties. Changing EU law is very hard, but the interpretation of EU law can be changed more easily. In terms of their genome profile the new interspecific crossings (like Solaris, Regent and Johanniter) have 90-95% vinifera genome and 10-5% non-vinifera genome. Officials who are responsible for checking new varieties (for patenting) look at 40-50 morphological characters, and the morphology of the leaf or shoot tips of vinifera and non-vinifera is quite distinct. The Bundesortenamt (Federal Plant Patent Office) is based in Hanover, with a sub-station for grapes in Hassloch in Germany’s Pfalz region. It was asked to see if the new hybrids differed in any way fom viniferas except in their disease rsistence. This attribute was excluded. It included the taste and appearance of grapes and wine quality. It said it could not distinguish any morphological differences between Regent and vinifera, nor any differences in wine quality. And so from the 1996 vintage the Bundesortenamt allowed it for quality wine for the first time. Previously it could be used only for table wine. So the law remained unchanged but its interpretation was changed.’

PIWI Vine breeders: Valentin Blattner.

My view: I support PIWIs for three reasons:

  • PIWIs make organic and Biodynamic wine growing much easier, whilst reducing or eliminating the use of controversial treatments allowed in Biodynamics and organics such as copper-based sprays.
  • PIWIs can be very cost-effective in terms of labour and use of energy and raw materials.
  • The best PIWI wines I have tried were pleasant, well balanced and with enjoyably easy to appreciate fruitiness.

PIWI varieties

RedRegent. | Rondo

White: Cabernet Blanc. | Johanniter. | Orion. | Seyval Blanc. | Solaris