The Arroyo Seco AVA, part of California’s Central Coast, is a cooler part of the state, home to plantings of Chardonnay, Pinot Noir, and Sauvignon Blanc, among other grape varieties. Today, the region is staking a claim on Sauvignon Blanc as a signature variety – but not just any Sauvignon Blanc. Instead, a single clone, known as Sauvignon Musqué, is making the move from the tech sheet to the back label to the front label. It’s not the only clone to do so, either. More and more producers, especially on the West Coast of the US, are betting on single clone wines. Is a winemaking detail like clonal selection really something wine drinkers need to know about?
Unsexy reproduction
The sci-fi name may give “clones” a certain appeal, but there’s little modern or exciting about them. After all, a clone begins by avoiding sex. Genetically speaking, grape vines are complex. “Vinifera harbors level of genetic variation an order of magnitude greater than humans,” according to the Institute of Genomic Diversity at Cornell University. So when grapes reproduce sexually, the “seed” may not resemble either of its parents at all; think of how different Pinotage can be from its parents, Pinot Noir and Cinsault. Reproducing a grape variety via sexual reproduction is almost impossible. The grape can indeed fall far from the vine.
But growers want consistency, so for centuries they have indulged instead in “vegetative propagation.” When growers want new vine, they cut off a limb from a vine they like and plant it or, post-phylloxera, graft it to rootstock. The new vine is genetically identical to the parent, and will produce the same grapes, right down to details such as the shape of the bunch and rate of ripening. This is cloning, without the test tubes and scientific apparatus associated with Dolly the Sheep.
In this way a Merlot vine is a Merlot vine is a Merlot vine. Or would be, except that vines are prone to mutate on their own. When this happens, the resulting vine is still considered to be the same variety, but may have developed some different characteristics – looser bunches, perhaps, or a tendency toward higher yields. In simple terms, this becomes a new clone of the same grape variety.
Standard practice has been to maintain a mix of clones in the vineyard, and therefore, in the final wine. In traditional vineyards the mix of clones might have been more haphazard, but nurseries and industry organizations like the Foundation for Material Plant Services (FPMS) in California and the Etablissement National Technique pour l’Amelioration de la Viticulture (ENTAV) in France have systematised and catalogued a substantial number of the grape clones in existence. Today’s growers can pick and choose not just the grape that matches their growing conditions, but the specific clone as well.
Growing in popularity
Hanging your hat on one clone is unusual, but one of the fastest growing wine styles of recent decades owes its existence to single clone wines. “I think it’s very lucky we brought back that very clone, UCD1, from UC-Davis,” says New Zealander Kim Crawford, founder of the eponymous brand and now his latest project, Loveblock.
And when Crawford says “we,” he means the New Zealand wine industry as a whole. UCD 1 is considered a vital part of the “formula” for their now-classic Sauvignon Blanc style, and still accounts for more than 90% of the Sauvignon Blanc plantings in Marlborough, even if it never gets a mention on the label.
A similar accident brought Sauvignon Musqué to Arroyo Seco. “I believe it was in the mid-70s or so,” says Mark Chesebro, owner and winemaker at Chesebro Wines. “Arroyo Seco Vineyards, a long-time grower in the area, had what was called an FPMS ‘mother vineyard’ where they maintained selections of vines that UC-Davis had cleared and had been imported correctly to use them for propagation.”
Chesebro says that Sauvignon Musqué was one of the Sauvignon Blanc clones in that collection. “Well, it turns out the Musqué clone had a minor virus, so it had to be decertified,” he continues. “Arroyo Seco was going to pull it out of their nursery so they could maintain certification status. The story goes that Doug Meador from Ventana Vineyards decided he wanted to grow it and propagate it even though it wasn’t certified any more, so he sort of kept it from going into oblivion. Ventana became very well-known for their Sauvignon Blanc.”
Why is Arroyo Seco sticking with the Musqué clone, if UCD 1 is No. 1 for New Zealand? Clones need to match their growing conditions, just as grape varieties more generally do.
“One thing is that the standard Sauvignon Blanc clones that are available in California don’t do well in as cool a climate as we are,” says Chesebro. “They take a long time to get past the very heavy vegetative flavors and get into something a little bit more interesting. You have to goad them to pretty high ripeness.”
In Napa, Beaulieu Vineyards conducted similar research on Cabernet Sauvignon around the same time. “In 1980,” says Trevor Durling, Chief Winemaker at Beaulieu Vineyards, “we began a series of trials in conjunction with UC=Davis to identify Cabernet Sauvignon clones best suited to our terroir.” Durling says they grafted 14 clones, selected from around the world, to rootstocks and evaluated their wines for more than a decade. “From these trials, we chose two clones (numbers six and four) for our Beaulieu Vineyard wines,.” he says.
One of the surprises of the research was that the two preferred clones were not recent imports from Bordeaux, but clones that had existed in the New World for some time. In the 1880s, University of California professor Eugene Hilgard planted Clone 6 Cabernet Sauvignon, which is also called the Jackson clone, at the university’s field station at Jackson in the Sierra Foothills. It was abandoned until about 40 to 45 years ago, when then-UC professor Austin Goheen rediscovered the old vineyard, identified varieties and took cuttings.” Clone 4 had been isolated in Argentina before being imported to California. Durling says they complement each other, Clone 6 imparting structure and intensity, and Clone 4 a lusher texture with softer tannins.
While Beaulieu blends both clones into most of their Cabernets, they also produce single clone versions of each. Clone 6 Cabernet has become a favorite with other Napa producers, appearing on the label of wines from Bell Wine Cellars, Merryvale, and others. Bell was actually the first to release a “Clone 6” bottling, though they used the name “Jackson Clone” until 1999; Anthony Bell had worked on the Beaulieu research previous to starting his own winery.
While many single clone wines do seem tied to a certain terroir, other clones are becoming popular “solo artists” internationally. Gibbston Valley in Central Otago makes a Clone 95 Chardonnay, as does Byron and Alysian in California, and Red Hook Winery in Long Island.
The majestic clone
If there’s a grape where clones are most likely to come into the conversation, it’s probably Pinot Noir. Experts estimate that there are as many as 1,000 different clones extant, owing to the Pinot family’s great age. In fact, the other members of the Pinot family – Pinot Gris, Pinot Blanc and so on – are actually mutations of Pinot Noir, not children or siblings. So technically they are just wildly diverse clones.
Erath Winery, in Oregon, is one of several wineries to make single clone wines, offering wines from three different Pinot clones (115, 777, and Pommard) each from two different vineyards.
“For years we’ve had different clones planted in our vineyards side by side,” says Gary Horner, winemaker. He says it wasn’t unusual for him to keep individual blocks separate during the winemaking process, and “over the years we’ve seen that there’s a significant difference. The more I thought about it the more I thought it looked like potentially a nice educational tool. If you hone in and separate clones you’ll see that vineyard’s thread within the clones but you’ll also see the differences among the clones. You’ll see the vineyard statement, and you’ll also see the individual clone statement.”
Nonetheless, “My favorite wines here are the blended wines. I’m not knocking the clones; I would take Prince Hill Pommard clone every day of the week.”
Why the hesitation?
In fact, some experts look askance at single clone wines, calling them simple or monochromatic. “I find them to be expressive in a different way to wines made from multiple clones,” says James Tidwell MS, co-founder of TexSom. “Often, the focus is more precise on a particular attribute.”
Yes and no, according to Chesebro, at least for the musqué clone. “The thing that’s great about musqué in this area is that there’s this whole continuum of flavors you can develop from the same grape.” He says it shows jalapeño and cilantro notes when harvested earlier, then citrus elements, and finally more exotic fruits like white peach and honeydew melon. “So what a lot of people will do in this area is sequential picking. I’ll try to pick about 20% to 25% of it in the herbal range, then about half of it in the citrus range, and then the last quarter in the more exotic fruit range. And then I really find that blend really says what I want to say and I think really exemplifies what’s happening.”
The average wine drinker may be a long way from keeping track of their favourite clones, especially with their less than evocative names: 777, 667, and 115 don’t drip with romance. But the wines can impress, and add depth and variety to a wine list. “This is one more way to use branding to differentiate wines and indicate a certain style,” says Tidwell. “Any method to describe a wine that offers associative branding amongst a smaller set or for an individual wine seems to catch on.”
