Why Can’t We Create New Grape Varieties?

It’s an extraordinary thing, but Nature does a much better job of creating new grape varieties than Man. It’s hard to think of any new variety that was bred to purpose and has made interesting wine. Perhaps the best known man-made variety is Müller-Thurgau, produced in Germany in 1882 by a cross between Riesling and the table grape Madeleine Royale. The most widely planted grape in Germany, it has the important attributes of growing more easily and offering greater resistance to frost than Riesling. But it’s basically good for producing bulk Liebfraumilch rather than quality wine. In fact, breeding programs have generally had their greatest successes in producing new varieties that do well in marginal climates, often because they have greater resistance to cold weather. While useful in allowing the range of viticulture to be extended where natural varieties might not succeed, almost by definition this does not produce great wine.

There’s a strange view when creating varieties that crossing two extremes will lead to a new variety balanced between the parents. Genetics doesn’t necessarily work like that. Look at Pinotage, a strange cross between Pinot Noir and Cinsault created in 1925 in South Africa. The variety was appealing because it ripened early and achieved high sugar levels. Pinotage can be made in fresh and fruity styles for early drinking, or given exposure to oak to become a more serious wine, but perhaps the most significant fact is that nowhere do you find any claim for its typicity. There’s no core style for Pinotage akin to that for its Pinot Noir parent, and my own view on the rare occasions when I encounter a decent Pinotage is regret that the producer didn’t simply plant a better variety in those vineyards.

Another variety constructed along the same principles is Marselan, a cross of Cabernet Sauvignon and Grenache undertaken in the south of France in 1961. The idea was to provide a new variety that would give better results than the over-producers such as Aramon that were prominent in the area at the time. But Marselan has never really caught on – there are only a couple of hundred or so hectares grown – perhaps because like Pinotage it just doesn’t have any core character.

My view that Nature does a better job was reinforced when I encountered a new variety at Querciabella in Chianti. Querciabella’s former agronomist acquired a cutting of a old Cabernet Sauvignon vine in the Chianti zone and propagated it at Querciabella. But the grapes ripened earlier than other Cabernet Sauvignon plantings and didn’t taste the same. DNA testing showed that the vines are a new variety, resulting from a cross between Cabernet Sauvignon and Trebbiano Toscana. They call it Trebbiano Nero at Querciabella.

The wine reinforces the impression of Cabernet as a distinctive variety. Barrel samples of Trebbiano Nero show a Cabernet-ish character, although to my palate it is more like Cabernet Franc than Cabernet Sauvignon. It’s softer than Cabernet Sauvignon, a little earthy, and has a distinct note of tobacco on the finish. Tannins are more finely textured than Cabernet Sauvignon, but show as drier on the finish; perhaps actually it’s not so much that the tannins are drier, but that the fruits are less obvious. There seems to be a touch less acidity and freshness than Cabernet Franc. It supports the view that the typicity of Cabernet can range from herbaceous to herbal to earthy to tobacco, all depending on the variety, cultivar, and conditions. It will be interesting to see what Querciabella decide to do with their new variety.

All different grape varieties developed originally by spontaneous crosses between existing varieties. This is a rare process, because the grapevine is self-fertilizing, so it’s not common for cross-fertilization to occur. And of course the frequency has been much reduced since the practice of growing each variety in its own separate plot rather than co-mingling them in the vineyard. Even so, there might be any number of such spontaneous crosses that pass unnoticed because the results are unremarkable; it’s only when one gives interesting results that it gets picked out and propagated. When new crosses are generated deliberately, a somewhat similar process occurs, in that lots of progeny are generated, and the viticulturalist tries to select one that has useful properties. So why are the results of spontaneous crosses in the wild so much more interesting?