Grape clones: Learn by doing
The differences between clones for Ste. Michelle Wine Estates have been more subtle than significant.
Without published research on which grape clones are best suited to Washington State conditions, growers must rely on the experiences and knowledge of others.
Washington growers are encouraged to do their own clonal trials to learn what works best on their site, but should be prepared for many years of testing.
Ste. Michelle Wine Estates, the state’s largest wine company, shared insights into choosing clones for Washington during a recent statewide wine industry meeting. Ste. Michelle Wine winemakers are noticing differences from their Cabernet Sauvignon and Merlot clonal trials, but often the differences are subtle and can take years to shake out.
Kevin Corliss, director of viticulture for Ste. Michelle Wine, said that although a few clones of Riesling and Pinot Noir were planted in the 1960s to 1990s, it was interest from the company’s marketing department that prompted their clonal research. “The marketing folks saw California getting $100 per bottle for certain clones,”
Spurred by the heightened interest in clones, Ste. Michelle began clonal research in the late 1990s, establishing small commercial blocks that could serve as replicated trials. Eight clones of Merlot and six of Cabernet Sauvignon were initially planted. Because certified material was limited at the time due to a planting boom, the selection of clones was based primarily on whatever clean planting material was available from California nurseries, Corliss said.
Although he saw very few differences in the vineyard, the real goal of the trials was to see if there were discernible differences in the wine. For nearly two decades, Ste. Michelle winemakers have tracked chemical and sensory analyses of the wines, looking for
“The trends were easier to parse out with Merlot,” Corliss said, adding that FPS (Foundation Plant Services) Merlot clones 15, 1, and 6 have become the preferred clones, above the industry standard of clone 3. “But the trends were less obvious with Cabernet Sauvignon. And, we found for all of the clones, there was no silver bullet. Differences were subtle or not at all. We couldn’t say ‘ah-ha,’ this is the one.”
He also observed, especially in Cabernet, that the wine results were more strongly tied to site and management than they were to the clonal selection.
The Merlot and Cabernet Sauvignon research has helped guide Ste. Michelle in their recent plantings. Since 2000, the company has taken the multiple clone approach in its vineyard expansions, sprinkling several clones in small blocks of its estate vineyard plantings, Corliss said.
Ste. Michelle views clones as more important for wineries that use only estate vineyards for their grape source than for those that source from a variety of vineyards. In their estate vineyards for Col Solare, Northstar, and Spring Valley, multiple clonal selections have been planted to give winemakers different flavors as well as to continue the company’s clonal evaluations. At Cold Creek Vineyard, larger blocks of clonal selections have been planted.
“We’re going out on a limb by trying some selections that we have no experience with whatsoever, other than evaluations from other countries,” Corliss said. Merlot clones 1 and 15 have been planted at Canoe Ridge, expanding earlier work with Merlot clones, but they have also planted what he calls guesses—clones without previous Washington experience.
Col Solare winemaker Marcus Notaro has been with Ste. Michelle Wine since 1995, and at Col Solare since 2004. One thing he’s learned from years of making wines from their different clones is that it takes a long time to determine a site’s influence on a clone. The Antinori family of Italy, a partner in Col Solare, conducts clonal trials for 20 years before deciding which clones they like, Notaro said.
“You have to be patient—don’t rush to judgment,” he said. And expect to see variability between the clones from year to year.
“The differences are subtle to significant. Some
years, something significant may stick out, but other years, not. It’s usually not night-and-day or revolutionary differences, only subtle.”
Notaro describes the differences between clones in the wine as more of a step, like an important detail in a
As a winemaker, he’s interested in clones that help him create a certain style of flavors. He shared preliminary impressions from the Ste. Michelle clonal wines:
- Merlot 15—spicy, floral flavors, sweet tannins, and a long finish
- Merlot 1—jammy and fruity
- Merlot 2—dark fruit characteristics
- Cabernet Sauvignon 2—dark fruit flavors, rich tannins
- Cabernet Sauvignon 6—bright fruit, aromatic, moderate tannins
- Cabernet Sauvignon 8—cocoa, red and black fruits, moderate tannins
- Cabernet Sauvignon 10—dark fruit, similar to clone 2
- Cabernet Sauvignon 21—very different, more delicate with herbal aromas, moderate tannins
Blend or keep separate?
For winemakers wanting to learn if there are differences between clones, Notaro suggests that they keep the blocks separate during fermentation and in the cellar.
In some years, there can be significant differences in tannin extraction, choice of yeasts used, and fermenting techniques.
Should you blend or keep the clonal wines separate?
“Right now at Col Solare, I want to keep the wines separate so I can see what they do in my specific vineyard,” he said. But in the future, he may blend.
Notaro notes that he really likes having different clones if he’s sourcing from only a few vineyards. “I consider clones as another tool for the winemaker,” he said, likening clones to wine barrels. Each barrel adds something unique to the winemaking process.
Clones also have the potential to spread out harvest, which during peak crush times can mean that a tank is available. Ripening differences between clones are also critical to growers, especially if a location is on the edge of whether a variety fully matures or not.
He still believes that while site and management are important, clones can make improvements in wine quality.