A vine leaf is enough. From a few cells a genetic fingerprint of a grape variety can be taken today, and anyone with enough fingerprints in a database can identify parents, children and siblings, as in a paternity test. That this method turned the wine world upside down in the 1990s is owed above all to Carole Meredith at the University of California, Davis, who showed in 1997 that Cabernet Sauvignon is a child of Cabernet Franc and Sauvignon Blanc. To her went a young biologist from Valais who had earned his doctorate at the University of Lausanne with a thesis on a genus of the borage family: José Vouillamoz wanted to learn the technique in order to apply it to the grapes of his homeland.
Valais as a laboratory
For that question Valais was the best place in the world. Few other regions have kept so many old, distinct varieties alive: Rèze, Humagne Blanche, Petite Arvine, Amigne, Cornalin, Lafnetscha, Himbertscha. With support from the Swiss National Science Foundation, Vouillamoz collected their profiles and compared them with varieties from the Aosta Valley, Savoie and the rest of Europe. The Alps turned out to be not a wall but a web of kinships, and some Valais grapes are parents rather than children. Not every thesis held: the parentage of Cornalin proposed in 2003, Mayolet × Petit Rouge, was refuted by Agroscope in 2025, and that is exactly how the science Vouillamoz practises works.
To drop at the apéro
Grape varieties have parents just as we do, and a man from Valais finds them by DNA test: some 1,400 varieties fill Wine Grapes, the book José Vouillamoz co-wrote.
A book of 1,400 grapes
The wine world knows his name mostly for a book of nearly 1,300 pages. Wine Grapes, published in 2012 with Jancis Robinson and Julia Harding, describes some 1,400 grape varieties that become wine somewhere on earth, with origins, synonyms, flavours and, where known, parents; Vouillamoz drew the family trees. The book swept away many legends. California’s Zinfandel is Croatia’s Tribidrag, and so is Puglia’s Primitivo; many “ancient” varieties are younger than thought, and many names simply denote the same plant.
The stories of the Swiss grapes
In 2017 came Cépages suisses: histoires et origines, in German Schweizer Rebsorten, with the stories of the grapes that arose in Switzerland or survived only here. Vouillamoz lectures, leads tastings and happily argues about whether Chasselas comes from Egypt, Burgundy or Lake Geneva; the genetics favour home. So next time a Petite Arvine is in your glass, you may know that behind the wine stands not only a grower but a family tree, and that a man from Valais drew it.