This family tree, which incorporates that of Cabernet Sauvignon, is taken from Wine Grapes, the book I wrote with Julia Harding MW and Dr José Vouillamoz, and is the most complex therein. This is only partly because Pinot (Pinot Noir, Pinot Gris/Grigio and Pinot Blanc have identical DNA profiles) and an obscure eastern French, pale-skinned variety, Gouais Blanc, produced so many progeny. Their 21 known offspring include Chardonnay, Aligoté, the Muscadet grape Melon and the Beaujolais grape Gamay. But Gouais Blanc, encountered today occasionally as Gwäss, has also been shown to be a parent of dozens of other varieties including the great grape of Germany, Riesling, Chenin Blanc, Colombard, the middle European dark-skinned Blaufränkisch and Muscadelle, the third white-wine grape of southwest France with Sauvignon Blanc and Sémillon. Few of the other parents are known. (As in the diagram for Cabernet Sauvignon, question marks represent unknown, probably extinct, varieties.) This is particularly true of the relationships shown in the top right-hand corner which shows how, unexpectedly, the Pinot of Burgundy is related to Syrah and Viognier of the Rhône as well as to a host of Italian grape varieties, including those most famously responsible for Valpolicella.
‘Wine Grapes’by Jancis Robinson, Julia Harding and José Vouillamoz is published by Allen Lane (£120)
When geneticists at the University of California, Davis discovered the parentage of the ubiquitous Cabernet Sauvignon vine in 1997, they revolutionised wine knowledge, opening the door to an avalanche of revelations of relationships between varieties previously never associated with each other. By complex analysis of the DNA of some of the most important vine varieties they found that, just as any small child might surmise but no wine connoisseur had ever contemplated, the parents of Cabernet Sauvignon must have been the equally dark-skinned Cabernet Franc and, unexpectedly, the light-skinned Sauvignon Blanc. But, as you can see from the diagram showing the relationships between this particular family of varieties, many but not all of them common in southwest France, this was just a piece in a jigsaw puzzle, one that is not yet complete. DNA profiling demonstrates parent-offspring relationships but cannot identify which is the parent so, for example, Abouriou may turn out to be the parent of the surprisingly important variety Magdeleine Noire des Charentes (and grandparent of Merlot) rather than the offspring.
It is perhaps not unexpected that the Cabernets, Merlot, Cot/Malbec, Carmenère and Sauvignon Blanc turn out to be related. They are the most commonly grown varieties of Bordeaux (even if Carmenère is now more much more widely grown in Chile than Bordeaux). Folle Blanche/Gros Plant is grown to the north of Bordeaux in Cognac country and just south of Nantes at the mouth of the Loire. The Loire is Chenin Blanc territory so Chenin’s appearance here is not a total shock. Nor is Trebbiano Toscano/Ugni Blanc, another variety widely used for distillation in southwest France. But Savagnin comes from the other corner of France entirely – and makes a much more predictable appearance in the Pinot family pedigree, thus showing that, in a roundabout fashion, the great grape of Burgundy is related to the great grape of Bordeaux.