However people got the equation into their heads that lower winegrape yields equal higher quality wine, it’s certainly a formula with staying power. But up in the Pacific Northwest, Patty Skinkis is doing her best to dispel the persistent myth, and in so doing, she’s helping growers boost profits.
Don’t get her wrong. An Associate Professor and Viticulture Extension Specialist at Oregon State University (OSU), Skinkis realizes the value of crop management. But growers can overdo it.
Growers aren’t the only ones who buy into the low yield/high-quality myth. Skinkis guest-lectures on viticulture to a basic horticulture class at OSU for students of all majors. One day, just out of curiosity, she informally polled the class on the issue.
“All the students knew it by heart,” she says: “Low yield equals better quality.”
But as a scientist, Skinkis knew it wasn’t absolutely true. Curious as to where the myth came from, her research led to France where growers limit yields not so much for quality but to restrict production.
“Or, it could be that the highest-quality grapes can come for stressed or diseased plants that can’t put out a lot of fruit,” she says. “It has to do with naturally lower yields, not artificially lower yields. There’s some logic to it, but the application of it today is misused.”
Skinkis has been researching the issue ever since she came to OSU in 2007 and saw the widespread plantings, especially of the variety she came to focus on, ‘Pinot Noir.’
“When I first arrived in Oregon, I couldn’t understand why they were planting like crazy, but were then thinning so they wouldn’t produce so much, which made no sense,” she says.
Veteran Grower’s Take
Ted Casteel was a pioneer wine grower of sorts in Oregon, as he planted his first vineyard in 1978. Back then they didn’t do any thinning, but Casteel learned the dangers of over-cropping early on, as the 1984 crop came in at four tons per acre, and a lot of growers couldn’t get over 18 Brix, far short of the preferred 23-24 Brix harvest level.
That 1984 vintage led growers ― a collaborative bunch in the state’s famed Willamette Valley — to more seriously investigate thinning, as they weren’t interested in producing bulk wine.
“The profit is so much better when the wines are consistently good,” he says. “Mediocre wine is tough to make money on. Up here where we can’t set big crops, we have to go for the high end. We need to be on top of our game if we’re going to compete with the Burgundians and the Sonomans.”
While they needed to thin and were not exactly sure why, many growers tended to over-thin. That meant they were leaving too many profits behind and making wines that were too high in alcohol and tannins, Casteel says.
“Then Patty came along in 2007 and said ‘let’s find a scientific answer.’ She recruited 14 vineyards and they all did several treatments,” he says. “One of the advantages is that it created a cadre of practitioner/scientists — we know how to do real science now. She was taking the science out into the practitioners’ world; it wasn’t just a university trial.”
Today Casteel farms 100 acres of winegrapes at his Bethel Heights Vineyard, located near Salem, in the heart of the Willamette Valley. To say he has been satisfied with Skinkis’s research is putting it mildly.
“If I feel free to increase the size of my crop by one-quarter ton per acre over my 100 acres of vines, that’s 25 tons times $3,000 an acre — $75,000,” he says. “And the results of this trial have yielded me way more than that.”
Skinkis immediately embarked on yield management trials because the industry was so keenly focused on yield. It was understandable, as the state’s ‘Pinot Noir’ growers are focused on top quality, seeking ultra-premium wine prices.
“Growers said, ‘We know when we restrict yield we can ensure adequate quality,’ but that didn’t make sense to me. Yields should be based on size of canopy,” she says. “We have big luscious canopies that can support a large amount of fruit. In some years, growers were cutting off 25% to 50% of the fruit, and Pinot isn’t a heavy yielder.”
The initial crop-thinning trial began in 2011 and covered two sites, one in the Willamette Valley and one in Southern Oregon.
“I was told by growers that it was great information about these two sites, but doesn’t say what they should do in their vineyards,” she recalls. “The only way we were going to fully understand this is to get this out to the vineyardists and winemakers themselves.”
So she stepped up the trials in 2012 with a core group of growers and winemakers who wanted to get involved. There have been a total of 24 growers in the years since, with 10-15 participating in any given year.
“They do all the trials,” she says. “I crunch the numbers.”
It’s a significant time commitment for the growers, as besides carefully monitoring cluster thinning, they had to do the data collection. Growers had to pick two to five crop-thinning levels on a cluster-per-shoot basis. They began noticing the difference.
“The most common now is 1.5 clusters per shoot,” says Skinkis, “but before I started it was 1 cluster per shoot. Others only remove wings and thirds and end up with about 2 clusters.”
Then they make the wine. After two years of aging, which is generally the age when consumers get ‘Pinot Noir’ in the marketplace, Skinkis takes the bottles and does sensory analysis.
Her colleague Elizabeth Tomasino, Ph.D., an Associate Professor at OSU’s Oregon Wine Research Institute, has been running wine tastings since the first vintage in 2012.
“There’s a lot of data,” says Skinkis. “We hold an annual collaborator meeting for the participating winemakers and growers, who see the data first. They get everyone else’s data too, though it’s coded.”
Interestingly, the differences in quality from the various treatments weren’t nearly as great as even Skinkis expected. And they certainly don’t justify leaving so much fruit behind. Growers have taken the results to heart.
“Since the project started, we have seen increases in yields across the state,” she says. “On average, they are up about a half ton per acre. In 2012, it was 2.2 tons per acre, and now it’s 2.7. A half-ton per acre increase is nothing to sneeze at.”
Besides the myth that lower yields equal high quality, Skinkis has been able to disabuse growers of the notion that smaller crops ripen more quickly.
“In fact, if you have too low a crop, the plants get lazy. Ripening doesn’t speed up because the crop is smaller,” she says. “People always crop-thinned to speed ripening, but that is not an observed effect.”
As might be expected, with the yield/quality myth so pervasive, Skinkis got a lot of pushback from winemakers at the beginning.
“Some still don’t fully wrap their arms around it. Certain winemakers are very involved, but there are others who aren’t really involved because they still keep this concept at arm’s length,” she says. “That’s a tough nut to crack, doing away with that old paradigm of tons per acre. We do see it happening, but there is still that image. Just because we’re producing high-end wines doesn’t mean we don’t want to do it economically.”
One winemaker who appreciates the research is Florent-Pierre Merlier of Van Duzer Vineyards in Dallas, OR. Though he’s quick to note that he hails from Burgundy, which is not so tied to the yield/quality notion as those from other parts of France, such as Bordeaux.
He says such research is unusual in the world, especially the way it’s been done. There has certainly been a lot of crop load research, but it was not over such a wide region with so many wineries involved.
“We have wineries from 5,000 cases to a half-million cases,” he says. “The differences that we see in crop load and data was really wide, and that’s what makes this project so interesting.”
Like Skinkis, Merlier was also surprised by the lack of effect lowering yields had on quality.
“I was expecting to see that by playing with the amount of fruit left on the vine there would be more chemical differences in the wine, and we didn’t necessarily see that,” he says. “Although, there can be differences in vineyards year to year.”
Merlier also notes that from the very beginning the project has not been just about the vineyard, it has been about the winery. It’s the research on wine production that makes it interesting, he says, as that’s where it counts.
Skinkis appreciates the winemakers’ participation in the project because it challenges their long-held belief in the yield/quality myth. But those wineries who have participated and learned their lessons have certainly benefited.
“Those who adopted an increase in yield have been able to return more profit,” she says. “We just have to get the marketing people to let go of the yield/quality relationship.”
Think Pounds Per Foot
In sum, Skinkis says vine health and how you manage that vine will have more impact on quality than the yield will have. She hopes that in a few more years she can give actual numbers for guidelines.
For now, she recommends growers think in terms of pounds per linear foot, not tons per acre.
“Pounds per linear foot lines up well,” she says. “In ‘Pinot Noir,’ it was .7 to .8 pounds per linear foot before we began the research. Now we think (the desired ratio) is more like 1.1 to 1.2 lbs. per linear foot. Talk pounds per linear foot, not tons per acre. The latter is just easier; it doesn’t make any sense horticulturally.”
Vines have a huge capacity to adjust on their own, Skinkis says. If you have a distressed vineyard, you have lower yields. If healthy, you have more yields. Manage each accordingly, as there is no one standard situation.
The research project has generally been a huge success, although she says it’s important that all the ramifications be fully understood. In the past couple of years, she says her work has started to attract the attention of growers around the country, but a lot of them get it misconstrued.
“They say, ‘Patty Skinkis says I don’t have to crop thin. No, I’m not saying that,” she emphasizes. “Slight crop thinning can enhance quality for sure. But it’s really on a site-by-site basis ― one thing we have found is it’s not consistent.”