Busting the low-yield myth
The size, condition, and character of the canopy determines the ability of the vine to ripen the fruit, and the effective crop load.
Some winemakers still insist on low yields regardless of the vine’s balance or capacity to ripen fruit to maturity. In some winery circles, these Zinfandel grapes could be candidates for cropload adjustment.
Photo by Melissa Hansen
One of the most contentious issues between grape grower and winemaker is the long-held belief that lower yields make better wines. Though research has uncoupled the linkage of low yield to premium wine, some U.S. winemakers still cling to the European tradition.
Dr. Nick Dokoozlian, vice president of viticulture, chemistry, and enology at E. & J. Gallo Winery, one of the world’s biggest wineries, says winemakers in Europe believe low tonnage equates to quality, a perspective he believes is prevalent throughout America’s wine industry. It’s no wonder, he mused, considering that roots of the U.S. wine industry and culture came from Europe, where grape growing and winemaking go back thousands of years and the industry is steeped in tradition.
“If I were growing grapes in Europe and trying to make decent wines—based on their shallow soils, natural precipitation, virus-infected plant material, and other variables—I’d be thinning crop, too, to try to get quality,” Dokoozlian said.
But New World vineyards in the United States, especially eastern Washington, with carefully applied irrigation and managed canopies, are vastly different than the French vineyards.
Dokoozlian took part in a panel discussion debating the myth that low yields always mean better wine quality held during a winter meeting of the Washington Association of Wine Grape Growers. The panel included: grape grower Tedd Wildman of StoneTree Vineyard in Mattawa, Washington; Eric Brasher, wine and vine consultant from Portland, Oregon; and Brennon Leighton, winemaker for Efeste Winery of Woodinville, Washington.
Although the panelists agreed that low yields do not always make better wine, they also agreed there are still winemakers out there hanging onto the myth.
Leighton said that as a winemaker, he looks for phenolic development in a vineyard and strives to achieve as much phenolic ripeness as possible in the berry without losing acidity.
“There is correlation between quality and yield in the sense that there’s a mid-area where it really works,” Leighton said. “Quality goes down when you overcrop, and it also goes down when you undercrop.” He tries to find balance in the vineyard and often hangs more crop in a warmer year.
Consultant Brasher, with clients in Oregon and Washington, believes there is a more pervasive change in quality due to yield when growing grapes in marginal climates. He also believes that thinning in cool climates is sometimes justified to hasten ripening. In warmer climates, the bell curve of quality is broader and there is less quality difference between yields than in cooler regions where grapes might have difficulty ripening in cool years, Brasher explained.
Historically, winemakers trying to reach phenolic maturity have used lower yields as an easy way to have a conversation with the grower to ensure that ripeness can be reached. “This conversation has helped develop the myth that you automatically hasten phenolic maturity by reducing crop load,” Brasher said, adding that phenolic maturity has been the driving reason winemakers he’s worked with in the past have asked growers to drop crop.
Sharing a grower’s viewpoint, Wildman said that each vineyard has a sweet spot when vines are in balance, but the sweet spot is different for each vineyard and depends on many variables, from site and variety to weather and canopy. Some of the state’s highest quality grape years have also been years of the highest average yields, he noted.
Wildman stressed that crop load is important, but not so subjectively that it should become the driving factor behind winemaker decisions. “There’s this European, mythical view of ultralow crop that seems to be ingrained in the wine industry and winemakers,” he said, adding that the U.S. wine industry has a lot of historical baggage and tradition tracing back to France.
“There’s good reason why French vineyards tend to crop low, and it’s usually an artifact of the soil, site, vine density, age of the vines, and such,” he said.
Winemakers, perhaps unconsciously, gravitate toward the low end of the scale. And while every vineyard has a different sweet spot, when winemakers go beyond and below that theoretical sweet spot artificially, just for the sake of low crop because it’s a talking point, it’s a mistake, and the myth should be busted.”
Crop load management is best done by pruning, he said, adding that while he prunes aggressively because he’s on a low-vigor site and not worried about overly vigorous vines, some growers tend to leave extra buds when pruning to compensate for spring frosts and must later come back to thin the crop. Even with knowing his bud count and with his severe style of pruning, he still can have a problem of higher cluster counts than desired.
Wildman said he’s had some years where yields ended up a ton more per acre than what was planned. “But if the vines seem to be in balance, I let it hang, and so far, it’s worked out and I’ve not had complaints.”
For winemakers who insist on low tonnage, Wildman suggested that growers use contracts based on acreage instead of production or yield. He believes acreage contracts help remove conflicts of interest on the part of growers who may want to maximize tonnage and keep winemakers from making unreasonable demands.
Better metrics needed
Gallo’s Dokoozlian believes the industry has difficulty defining yield and quality with the metrics currently available. Yield is typically defined as tons per acre, but more is going on in the vineyard than just yield. “We fail to integrate what’s really going on. It’s not just the amount of fruit, but it’s really the canopy—size, condition, and character—that determines the ability of the vine to ripen the fruit and effective crop load,” he said, adding that the industry hasn’t paid enough attention to canopy size and capacity relative to yield and quality.
“Vineyardists don’t have compositional metrics in place to look beyond sugar [soluble solids] and color when talking to winemakers. Sugar and color are just two of the many components involved with grape and wine quality.”