Varietals - What are they anyway?

Many wine lovers throw around names like Cabernet Sauvignon and Sauvignon Blanc without stopping to ask what those terms mean. How do they differ? Where did they come from? We begin an article (using some “borrowed” material) on grape types and their relationships.

Species Basics
Grapes grow on vines. Vines are fast growing, climbing or trailing plants that typically lack sufficient wood structure to support their fruit. They grow along the ground or on naturally occurring supports. When cultivated by farmers, grapevines are generally trellised for support, but some are allowed to grow as small bushes (head-pruned) with very short shoots from which the grape clusters hang.

There are twelve species of grapevines, but only two are used to make wine. Vitus Labrusca is native to North America and includes the inferior Concord, Niagara, and Catawba grapes. Today they are most closely associated with New York State, but centuries ago they covered the northeast and are the reason early maps referred to North America as “Vineland.” Vitus Vinifera, considered superior for wine, is native to Europe, the Near East, and perhaps northern Africa. All the major wine grapes that we are most familiar with are of this species, and they have been transplanted around the world. The earliest evidence of vine cultivation comes from southwest Asia or southern Transcaucasia (Armenia and Georgia) about 3500-3000 BCE. Wine was made from wild grapes much earlier; evidence suggests resinated wines were made at the site of Hajii Firuz Tepe in the northern Zagros Mountains of Iran circa 5400-5000 BCE.

Varietal Basics
Although grapevines were happily growing before modern man ate the grapes and later learned to make wine from them, there were already many varieties of grapevines within each species. Due to Darwinian pressures, Vitus plants adapted to local conditions. Although they would later be classified as the same species, there were already may different subspecies of grapevines before people learned to cultivate and breed them for particular characteristics. Just as the dog (a domesticated subspecies of wolf - Canis lupus), cat, (Felis catus) corn (Zea mays), tomato (Lycopersicon esculentum), etc. have many different varieties, subspecies, breeds, or whatever you wish to call them, so grapevines have many different varieties or varietals. The great majority of these are naturally occuring; a few have been deliberately bred.

Subvarietal Basics
To make matters even more confusing, even within a common, recognized grape varietal, breeders have selected for specific traits to the point where we talk about specific “clones” or cultivars. For example, vineyard managers can chose from over forty recognized clones of Pinot Noir. At the research level, hundreds of Pinot clones have been studied. Clones have subtle differences such as speed of growth and ripening, spacing of grapes within a cluster, thickness of skin, production yield, cluster and berry size, as well as bouquet and flavor characteristics. Clones are genetically identical and are reproduced without seed directly from a bud or shoot.

What Does it all Mean for Taste?
The interdependent factors that affect wine flavor are the varietal(s) of grape used, the location where the grapes are grown, the treatment of the vineyards, the skills of the vineyardist, and the equipment and techniques used by the winemaker, as well as the skills in applying them.

Arguably, the varietal of grape used is the dominant factor in wine flavor. Take any world famous vineyard (or even an entire Appellation), plant it with a different variety, and the wine from there would become unrecognizable even if treated in the same way and by the same hands. Different grape varietals have differing aroma and flavor characteristics. Varietal character, however, while somewhat predictable, is not precise. Variations occur, for virtually all vines are propagated by cloning, and some grape types are more prone to clonal variation.

How Many Varietals Are There?
There are over 10,000 documented varieties (varietals) within species Vitis vinifera. Commercially, three of these are used to make raisins and less than a dozen for table grapes. While about 230 are noted for making wine, less than 100 varietals have a significant following even among wine geeks. The selection in most good wine shops is perhaps 50 (slightly more red than white). The general wine consuming public tends to focus on about 15 of these.

How are the Grape Varietals Related?
While the history of grape varietals and their relationships are murky, genetic studies have clarified the situation to a great extent and have produced some surprises. Dr. Carole Meredith spent more than 20 years in the Department of Viticulture and Enology at the University of California, Davis, America’s premier academic university devoted to the science of grapegrowing and winemaking. Meredith’s main focus of study was grape genetics, and her research used DNA typing methods to discover the origins of wine varieties such as Cabernet Sauvignon, Chardonnay, Syrah, and Zinfandel. She recently retired from academic life to concentrate on making wine herself alongside her husband Steve Lagier under the Lagier Meredith label.

AN EDITED INTERVIEW BETWEEN DAVID GRAVES (SAINTSBURY) AND DR. MERIDITH

What gives rise to a “new” variety (varietal)?
A new variety starts as a single seedling plant that has two parent vines-a male parent that contributes the pollen to the female parent that bears the fruit. Today this cross-pollination can be done deliberately by a grape breeder, but until about 200 years ago, all cross pollination between grapevines was natural. All of our classic wine varieties seem to be the result of natural cross pollination between two parent varieties.

When the fruit on the female parent vine gets ripe, it falls to the ground or is eaten. Some of the seeds inside eventually germinate and grow into new grapevines. Like human offspring, each seedling grapevine differs from the two parents and also differs from all other seedlings of those two parents. So even though two parent grapevines may produce a lot of seedlings, a variety that is their offspring comes from only one seedling. All the vines of a specific variety in vineyards all over the world have been propagated by cuttings or buds from that first single seedling grapevine.

What are the parents of Pinot Noir and Chardonnay?
We do not know the parents of Pinot. It is such an ancient grape that we have no techniques or written history to bring to bear on the question. Keep in mind that Pinot “Noir” is just one form of Pinot. We say Pinot instead of Pinot Noir or Pinot Blanc or Pinot Gris because those three are all color forms of the same variety and all three have the same DNA profile. So DNA studies of parentage cannot distinguish between them.

Our studies show that the parents of Chardonnay are Pinot and Gouais Blanc. So we know one of the parents of Chardonnay is a form of Pinot. The other parent of Chardonnay is Gouais Blanc, a variety that was once widely grown in northeastern France. Considered a mediocre variety, it was grown only by peasants on land not considered good enough for the noble Pinot Noir. Gouais Blanc is not a French variety. It is a Central European variety that may have been brought to France by the Romans. The Roman Emperor Probus was from what is now Croatia. In the 3rd century A.D. he is said to have given the Gauls a gift of a grape from his homeland. This may well have been Gouais Blanc.

How old are Pinot Noir and Chardonnay?
This question is easier to answer for Pinot Noir than it is for Chardonnay. Pinot Noir was already being grown in Burgundy when the Romans arrived there 2,000 years ago. The Roman agricultural writer Columella described a grape variety in the 1st century A.D. that was most likely Pinot Noir. So we’re pretty sure that Pinot is at least 2,000 years old.   The age of Chardonnay is more difficult to pin down. It must be younger than Pinot because Pinot is one of its parents. But it can’t be older than the date at which its other parent, Gouais Blanc, was introduced to France, which was probably in the 3rd century A.D. Chardonnay has been confused with other varieties (e.g., Pinot blanc and Melon) and has had many names, so it’s not at all clear when Chardonnay first appeared. It seems to have been recognized as a distinct variety by the 1300s, but may well have been around before that. So the best we can say is that Chardonnay is at least 700 years old, but could be as much as 1700 years old.

Where did Pinot Noir and Chardonnay come from?
Pinot Noir most likely came from northeastern France or southwestern Germany. It is only 1 or 2 generations removed from the wild vines of that region. Chardonnay was born in Burgundy.

I have read that Pinot Noir is “genetically unstable.” What does that mean?
Sometimes one part of a Pinot Noir vine will look different than the rest of the vine. The leaves may be more hairy or the fruit will be a different color. This is largely because the color and leaf appearance are determined by the outer layer of cells. The inner layer of cells is sometimes genetically different than the outer layer. If those inner cells make their way to the outer layer, their genetic difference may eventually become visible if they becomes part of a bud that produces a shoot. But these layers exist in all grape varieties. We simply don’t know why the differences appear more frequently in Pinot than other varieties. Perhaps because Pinot is older than almost all other grape varieties, there has been more time for genetic differences to accumulate in the inner cell layer. There may be other reasons that we simply don’t understand yet.

What is a clone? Why so many? Are they all different? How did those differences arise?
A clone is a variant within a variety that has some difference of interest to grape growers and/or winemakers. The older the variety is, the more variants exist because there has been more time for the differences to arise. The differences can be visible like berry size or cluster shape, or they can be differences like aroma or acidity. Pinot Noir, being among the oldest varieties, has many known clones. The younger Chardonnay has a smaller number of clones. The very young variety Cabernet Sauvignon has only a few clones, and they are not very different from each other.

Lots of clonal variation will exist in old vineyards in the original home of a variety (such as old Burgundy vineyards for Pinot or Chardonnay), but a variant only really becomes a “clone” when a variant vine is identified by someone as being of interest and cuttings are taken from it and then given a name or number and propagated separately.

A clonal difference arises as the result of a naturally occurring mutation in a single cell at the growing point of a grapevine shoot. As the cell multiplies, it will come to occupy a larger and larger proportion of the cells in the shoot tip. The shoot tip may eventually consist entirely of this new cell type, and eventually an entire shoot may carry the new mutation in every leaf and berry. If the mutation affects something of interest to growers and/or winemakers, such as berry size, color, or flavor, then the part of the vine that has the new characteristic may be preferentially chosen as a source of buds or cuttings for new vines. But an uninteresting mutation may never be noticed at all and may or may not persist in the vineyard by chance alone.

Why were Pinot Noir and Chardonnay the dominant grapes in Burgundy and not in Bordeaux, for example?
Pinot Noir probably arose from a wild grapevine in Burgundy (or nearby in Champagne or southwestern Germany). Its parents or grandparents were likely wild vines. For that reason it is well adapted to the cool growing conditions of Burgundy. The quality of the wine from Pinot Noir was well-recognized 2,000 years ago as the best of any grape in the area, so the variety was widely planted by those who were wealthy enough to grow crops other than those needed for subsistence. But there were very few other varieties at that time to choose from, so Pinot became a dominant grape in Burgundy because it was born in that region and produced fruit of recognized quality.

Chardonnay was widely planted in Burgundy because it was also recognized for its superior wine. Chardonnay was also born in that region, but we know that its parents are Pinot and Gouais Blanc.

Neither Pinot nor Chardonnay could have been dominant in Bordeaux because both varieties were born in northeastern France, which is nowhere near the Bordeaux region, and grape varieties were not shared much between different parts of France. (Two exceptions are Cabernet Franc and Sauvignon Blanc, which are important in both the Loire and Bordeaux regions.) Had Pinot and Chardonnay by chance been taken to Bordeaux long ago, they might have become important there. The warmer Bordeaux environment would not have brought out the best in Pinot Noir, but Chardonnay should have done well there.

Are Ruländer, Pinot Gris, and Pinot Grigio all the same variety?
Yes. They are all just different names for the same variety. It’s called Ruländer or Grauer Burgunder in Germany, Pinot Gris in France, and Pinot Grigio in Italy. Similarly, Pinot Noir is called Spätburgunder in Germany and Pinot Nero in Italy. Most of the old wine grapes have different names in different places. In France alone, at least 30 different names are known for Pinot Noir and there are more than 40 for Chardonnay!

What is the Origin of Cabernet Sauvignon?

Wine enthusiasts use only superlatives to describe Cabernet Sauvignon, a dark cherry-red wine derived from the grapevine of the same name. It has been referred to as the patriarch of the red wines. Now the second most widely cultivated wine grapevine in the world, Cabernet Sauvignon is known to have been growing in vineyards of the famed Bordeaux region of France as early as the 17th century.

But its origin had been lost in history until UC Davis Professor Carole P. Meredith and doctoral candidate John Bowers, using DNA “fingerprinting” techniques, conclusively discovered that the Cabernet Sauvignon vine is the offspring of the Cabernet Franc and the Sauvignon Blanc varieties. This solved a centuries-old mystery that had baffled scientists and wine aficionados alike. The findings, reported in the scientific journal Nature Genetics, were accompanied by a news and review article by James Luby, a grape geneticist at the University of Minnesota, who explained the historical significance of the research.

Carole Meredith and John Bowers had been working for several years on genetically characterizing grapevines. (Establishing wine grape vineyards is a costly undertaking, and vineyard owners can’t risk mistakenly planting the wrong variety.) Grapevine varieties can be characterized according to physical features of their leaves, fruit, and tendrils, but these traits can easily be influenced by environmental conditions; furthermore, grapevines are usually propagated from dormant pieces of stem which lack the fruit and foliage necessary for visual identification.

During the past decade, a method of genetic identification has been developed that has become known as DNA “fingerprinting.” This technique relies on characteristic patterns in a plant’s or animal’s genetic material (DNA), much as traditional fingerprinting relies on characteristic patterns in the whorls of the fingerprint. This new technology has proven so accurate that it is now commonly used to establish the lineage of racehorses, to settle paternity suits, and even to provide evidence in murder cases.

Meredith and Bowers developed genetic fingerprints for 51 wine grape varieties including Cabernet Sauvignon. They crushed young grapevine leaves from each of the varieties, extracted DNA from the leaves, and examined 30 distinct DNA sites known as “microsatellite” markers that differed from the surrounding DNA in chemical makeup. They then used statistical analysis to determine the likelihood of the Cabernet Sauvignon microsatellite fingerprint deriving from the fingerprints of any two of the other varieties. These analytical methods conclusively pointed to Cabernet Franc, itself a distinguished red wine grapevine, and Sauvignon Blanc, which yields a white wine grape, as the genetic parents of Cabernet Sauvignon.

“Although the similarity in names might suggest that Cabernet Sauvignon is connected to these other two varieties, the relationship came as quite a surprise,” Meredith said. “A close link between Cabernet Sauvignon and Cabernet franc has been suspected, but no one had any idea that Sauvignon Blanc was related.” She noted that the use in both names of the word “sauvignon” (derived from the French word for “savage” or “wild”) reflects the resemblance of the varieties to wild vines rather than any suspicion that a genetic relationship existed.

Meredith and Bowers suspect that Cabernet Sauvignon is the product of a spontaneous crossing between vines in an adjacent or the same vineyard. “It could have occurred no later than the 17th century, an era that precedes the earliest report of deliberate plant hybridization.... It is more likely that the cross occurred spontaneously.” Prior to the 17th century there were no reports of grape breeders deliberately making plant hybrids, and there would have been no practical reason to make such a cross.

The oldest recorded reference (that we know of) to Cabernet Sauvignon comes from the 18th century and Chateau Mouton. It is said that Baron De Brane ripped up his white wine grape varieties and instead planted a variety called Vidure. Vidure comes from the French words Vigne Dure meaning “hardy vine,” which describes the Cabernet Sauvignon vine perfectly.

When looking at the history of Cabernet Sauvignon, we see that its spread throughout Europe happened in the eighteen hundreds where it was known by many different names such as Petit Cabernet, Petit Vidure, or simply Vidure.

The history of Cabernet Sauvignon also shows us that the earliest record of its appearance outside of Europe was in Australia in the year 1820. Just a few years later, Cabernet Sauvignon was introduced into southern California.

What about Zinfandel?

America’s best grapes are of the species vitus vinifera and originated in Europe. Cuttings began to arrive here around 1820. Zinfandel first appeared in this country in the mid-1820s in the  catalog of a nursery in Flushing, N.Y. It may have been imported from Austria. In the 1840s, it was grown in hothouses in the Northeast and sold as a table grape. A decade later, it was introduced in California, and by the 1880s, it was the most popular grape in the state. Around that time, its name was fixed as Zinfandel. Previously, it had been called Zinfardel, Zinfendel, and Zinfindal, among other things.

In the first half of the 20th century, Zinfandel became one of the leading grapes in red wine blends. California jug wines had generic names that had actually been stolen from Europe. These wines, with names like “burgundy” and “chianti,” were blends that often contained large amounts of Zinfandel. In the second half of the 20th century as varietal labeling took hold, Zinfandel began to gain popularity as a varietal (a wine known by its grape’s name). It became something of a household word in the 1970s with the introduction of “White Zinfandel,” which is really a pale, sweet rosé made from normal red Zinfandel grapes.

Cabernet, Merlot, Sauvignon Blanc, and Chardonnay had clear counterparts in Europe. Zinfandel arrived here about the same time, but because record-keeping was spotty, Zinfandel’s exact European origin was unknown. The difficult and convoluted search for its origin began in the late 1950s. All that was known for sure was that it was of the same vitus vinifera species as the others and that it must be an obscure grape in Europe, because its locus was not obvious.

The first part of the scientific story began when Dr. Carole Meredith, professor and geneticist at the University of California - Davis and the world’s preeminent grapevine sleuth, determined though DNA tests that Zinfandel and the obscure Primitivo from Italy’s Puglia region were genetically identical. At first it seemed that Zinfandel originated in Italy. One problem with that theory was that Primitivo did not seem to have a long history in Italy.

The second part of the story involved Mike Grgich, one of California’s best-known winemakers, who had immigrated from Croatia in the 1950s. A grower of Zinfandel himself, he had always believed that Zinfandel was the same as a vine he had been familiar with back in Croatia called Plavac Mali. Scientists put these two parts of the story together and hypothesized that both the Italian Primitivo and the American Zinfandel originated as Plavac Mali in Croatia.

The final part of story began when Dr. Meredith went to Croatia in 1998 to collect samples. With University of Zagreb researchers and a former Croatian student of hers at Davis as translator, she collected Plavac Mali samples from dozens of vineyards. Back at Davis, DNA tests proved that none were the same as zinfandel!

Meanwhile, her Croatian colleagues kept looking. In September 2000, they found a single vine of what they thought was Crljenak Kastelanski (pronounced tsurl-YEN-ak kastel-AHN-ski). They sent a bit of it to Davis, but tests showed that it wasn’t Zinfandel either. Thinking that perhaps they had made a mistake, they went back to the same vineyard in 2001 -- six hours by car from Zagreb. It turned out that they had taken samples from the wrong vine.

Finally they got it right. Back at Davis, the Crljenak Kastelanski, Primitivo, and Zinfandel grapes were a perfect DNA match. So the answer to the story is that the grape we call Zinfandel and that the Italians call Primitivo originated in Croatia where it is called Crljenak Kastelanski. Plavac Mali turned out to be what Dr. Meredith calls “a son of zinfandel,” a cross between Crljenak and the Dobricic grape. 

What about Merlot?

The preoccupation with grapevine clones was a response to disease problems. By the 1950's many vineyards in France were in poor condition with heavy yield losses and vine life span cut to less than one decade – the result of disease buildup exacerbated by grafting practices and also by neglect during World War II. Vineyards in the U.S. were experiencing similar problems.

In 1955 Dr. Raymond Bernard led a French government team that addressed the crisis. They tagged hundreds of diverse, healthy-appearing vines. The team observed the vines for three years, looking for signs of disease. They then grafted healthy cuttings to new rootstock and continued to monitor them for disease. Eventually they made wine from each lot and tasted the wines with winemakers and industry experts. The result was a large library of disease-free, reliably performing "clones," which were identified simply by numbers such as "115" or "777." James Olmo, of the U.C.-Davis led similar efforts in the US but on a smaller scale.

The number of Pinot Noir clones far exceeds that of other varietals. One of the oldest grape varieties, it shows remarkable genetic diversity and mutability. In 1977 a viticulturist from Robert Mondavi winery recalled seeing 125 pinot noir clones in a single experimental vineyard in France. With the renaissance in American winemaking in the late 1960s, interest in these clones developed for disease-free stock and for vineyard characteristics such as early ripening (needed in cool climates), open clusters (where humidity is a problem), small berries for concentration etc., and for subtle differences in the quality and taste of the wines made from them.

Oregon was at the forefront of this movement, with pioneers such as Charles Coury, David Lett, David Adelsheim, and Dick Erath developing close ties with the French researchers and with Dr. Bernard in particular. Availability through U.C. Davis was limited at first and included Wädenswil clones, (named for a town on Lake Zurich which is home to the Swiss viticultural research center) and Pommard clones (named for a village in Burgundy). In 1975 Oregon obtained its own import license through Oregon State University - Corvallis. In 1984 Dr. Bernard came to O.S.U. to lecture and brought Pinot clones #113, #114, and #115 with him. In 1988 he sent #667 and #777, which had become known as "New" or "Dijon" clones after the university town where much of the French research had been done. When asked why he had so generously shared these treasures of French intellectual property, he replied, "there can never be too much good wine!"