What is a grape variety? What is a clone?
Today, labels on wines often include the name of the grape variety, clonal variant, vineyard source and winemaking technique. Don’t you feel that you need a course in botany and enology before opening the bottle?
Varietal labeling used to be illegal in France: a bottle could be assumed to contain those varieties that were permitted in a region. It was more important to know where the grapes were grown, and who grew them.
In the United States, Robert Mondavi changed all that in the 1970s when he began to name the grapes used in his wines, in order to distinguish them from false regional designations such as “Lake Country Chablis” or “Hearty Burgundy.” Now we all recognize “chardonnay,” “syrah,” or “riesling,” and look askance at wines without varietal designation.
This focus has narrowed the number of marketable grape varieties, since consumers don’t like to take risks with the unfamiliar. There are more than 10,000 grape varieties but we choose fewer than 20, with chardonnay, cabernet sauvignon, merlot and pinot grigio making up almost half.
A grape variety is always the product of sexual reproduction, where two existing varieties cross-pollinate to make a seed yielding an entirely new genotype of vine. The earliest grape vines, known as
“vitis vinifera var. sylvestris”
originated somewhere in the vast upland plain encompassing what is now Georgia, Armenia and Azerbaijan in eastern Turkey and western Iran. Eno archeologists have traced the proliferation of vines via DNA analysis in an effort to show a single origin (the “Noah Hypothesis”).
Like Adam and Eve, the first grape vines existed in both male and female, or
dioecious
forms, and these spontaneously cross-bred to create new varieties. Our human ancestors enjoyed fermented wild grapes before they began cultivating vines. Once they stopped roaming and settled down, they learned to propagate the vines that produced the best tasting fruit.
Most of the ancient varieties were still
dioecious
, but about 2- to 3 percent were self-pollinating, or hermaphroditic. Only the latter could be reliably counted on to produce a crop of grapes every year, and it must have taken close observation to identify these varieties (
vitis vinifera var. vinifera
) and propagate them via cutting or layering the parent vines.
Researchers have traced the domestication of wine grapes to the same region where other plants—such as wheat, lentils, chickpeas and rye—were first domesticated, in the headwaters of the Tigris and Euphrates Rivers of Anatolia. Computerized analysis of early languages points to a shared Indo-European root word for wine:
“win-o.”
Don’t you love deep scientific investigation?
Dating the residue found in ancient pots from northern Iran indicates that wine was made from domesticated
vinifera
varieties before 7000 B.C. Although these were hermaphroditic, because multiple varieties were indiscriminately planted closely together, they did cross-pollinate (as pollen from one vine could fertilize the ovary of another). Though most seedlings were inferior to the parents, over time some appeared with superior qualities that led growers to select and propagate them deliberately.
DNA analysis indicates that sometime around the 17th century in Bordeaux, a cabernet franc vine mated with a sauvignon blanc vine. Their babe was called “cabernet sauvignon,” a single vine that some vintner must have recognized and propagated by rooting cuttings. The ancient cab franc is also the father of merlot and carmenère.
Another “parent” variety—the much-scorned gouais blanc—engendered over 80 known varieties, including chardonnay, riesling, gamay and gewürtztraminer. Each of these had different mothers, making them distinct varieties rather than clonal variants.
Although every plant generation mutates about one cell in 300, only a tiny fraction of these DNA changes are functional. Still, over thousands of years enough changes occur to make clones of the oldest varieties distinctive. Pinot noir, pinot blanc and pinot gris are not, in fact, different varieties; they are clonal variations of a single ancient vine with mutations to DNA affecting skin color.
Today’s growers are on the lookout for clonal variation to create complexity in wines made from popular varieties. While some keep clones separate, others prefer a mixture of clones to protect biodiversity in the vineyard.
If you’re curious about varietal or clonal differences, enliven your winter evenings with comparative tastings. It’s fascinating to compare Southold’s Croteaux Vineyards’s rosé wines made from distinct clones of merlot. Or, to see what wine from an ancient vineyard with complanted varieties might have been like, try Channing Daughters’s Mosaico, a dry white wine made from pinot grigio, chardonnay, sauvignon blanc, muscat ottonel, tocai friulano and gewürztraminer—all grown, harvested, pressed and fermented together.
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