Taking the Temperature of a Lemberger
When it comes to pinpointing the perfect serving temperature for wine, Washington State University scientists are getting warmer.
While it’s often been said white wines are best served chilled and red wines near room temperature, sensory analyst Carolyn Ross is de-mystifying such anecdotes using a relatively new technique called napping. Napping, which comes from the French word for tablecloth (nappe), allows panelists to group their wines by similar traits on a placemat and then write down the attributes they used to choose the groups directly on their “nappes.”
“Panelists use their own language to cluster the wines and then we decode it,” Ross said. “The method requires some interpretation and is complicated for data analysis, but it can really help us understand how attributes change with temperature…while allowing panelists to use their own sensory language.”
In the study, twelve panelists tasted six different Washington State Lemberger wines at three temperatures: 50°F, 60.8°F, and 71.6°F. Physical chemistry predicts that the release of volatile components from a sample increase as temperature rises. This helps explain why, overall, panelists used flavor and aroma terms more frequently with higher serving temperatures than with lower serving temperatures.
“Researchers have shown that many products, when served cold, give off fewer aromas than warm ones,” Ross said. “That’s true of wine and other foods.”
Decoding the nappes
According to the study, Lemberger served at 50°F and 60.8°F left panelists with impressions of a wine that, compared to the wine served at the higher temperature, was sour, bitter, highly astringent, and low in aroma. The cooler wine samples were also described as smooth and thin in comparison to warmer wine samples, which is consistent with research on viscosity, Ross said.
Wines served at 60.8°F and 71.6°F were more frequently described as having spicy and berry notes than the 50-degree sample and panelists were more likely to use “sweet” to describe wines served at those higher temperatures, Ross said.
Sensing a difference in astringent mouthfeel
Ross found it interesting that panelists also grouped their wines by low and high astringency, actually discerning a difference in the tannin level and the intensity of the dry mouth feel that lingered after sipping a sample.
“Even though we didn’t require panelists to use intensities, we kept them qualified in our results because people tended to consistently distinguish between high and low,” she said. ”That was something we hadn’t seen in the previous study.”
Ross said this could be a function of the type of wine–in the past they used a Pinot Noir with lower tannin levels to bring out certain flavors. Each wine has its own qualities that can be influenced by temperature, she said.
“This is useful for those in the wine and hospitality industries who have thought this to be the case, but have lacked formal sensory science studies,” she said. “These industries can use this information to better showcase their red wines.”
Second Phase of ‘Vineyard Beauty with Benefits’ Begins—Again with Aid from Prison Inmates
In 2011, WSU entomologist David James began the Vineyard Beauty with Benefits Project to restore native habitats within and around eastern Washington vineyards while attracting beneficial, pest-eating insects and pollinators. James and other researchers conducted field and plot studies on more than 100 plants native to the region in the project’s first two years and identified those that showed the most promise.
Next month, James will begin the second phase: evaluating the top five plants in a vineyard setting to confirm their benefits to integrated pest management (IPM) and to determine impacts, if any, to wine grape production and quality. His work is supported by BIOAg and Washington Grape and Wine Research Program grants from the WSU College of Agricultural, Human, and Natural Resource Sciences.
“The short term impact of this project to the Washington wine grape industry will be identification of native, drought-adapted plants that will establish, grow, and survive well in vineyards,” James said. “They would also serve as a resource and habitat for beneficial insects responsible for controlling grape pests like spider mites, rust mites, leafhoppers, mealybugs, and cutworms.
“Long-term benefits of resilient and hardy native ground covers on wine grape IPM will be considerable in terms of sustaining biological-based pest control,” he added. “Substantial, industry-wide decreases in pesticide inputs and environmental contamination are expected within a few years of implementation, along with increases in farm profitability.”
There are no commercially available, proven IPM-enhancing ground covers that will survive in eastern Washington vineyards without regular irrigation, James said. The availability of one or more such ground covers would provide a significant and welcome benefit to viticulture in the region. The first phase of the Vineyard Beauty with Benefits Project revealed that possible candidates included yarrow, showy milkweed, Northern buckwheat, snow buckwheat, and mountain monardella.
“This project will, ultimately, identify the best native plant ground covers that can be used in vineyards to enhance and sustain biologically based IPM of wine grapes in eastern Washington,” he said. “It will also enhance conservation of threatened pollinator species like native bees and butterflies.”
Building on his earlier success with a Monarch butterfly pathway study, James is again teaming up with Washington State Penitentiary (WSP) inmates, this time for help with identifying and counting insects and mites. The inmates will be trained to use microscopes to examine grape leaf and sticky trap samples collected monthly from James’s test plots.
“The work we conducted with WSP in 2012 on rearing and releasing Monarch butterflies to understand migration routes was such a success, both in terms of research results and educational and mental benefits to the inmates, that we wanted to expand the possibilities of collaborative research,” James said. “If the marvel of metamorphosis as revealed by Monarch butterfly caterpillars can stir the souls of convicted felons, as it did, then I believe they will be held even more spellbound by the world they find under the microscope.”
Science of Wine is Topic of WSU Innovator Lecture April 4 in Seattle
What role does science play in the quality of wine? Thomas Henick-Kling, director of the Washington State University viticulture and enology program, explores this and other questions in “Science in Your Glass,” the WSU Innovators luncheon, 11 a.m.-1 p.m. Thursday, April 4, at the Fairmont Olympic Hotel in Seattle.
“Our understanding of all aspects of the winemaking process, from molecules to markets and from vineyards to bottles, underpins the wonderful success of the Washington wine industry,” said Henick-Kling. “This nearly $15 billion industry is an engine of job-creating vitality. I’m excited to be able to share some of the science that makes this all possible.”
The unique characteristics of Washington’s climate and soils contribute to the distinctive taste of its premium wines. But those same characteristics create challenges and opportunities for growers and winemakers specific to the Pacific Northwest.
WSU has partnered with state winemakers and growers since the 1960s to engage in cutting-edge research and provide hands-on education for a highly trained workforce. WSU researchers have helped growers select vineyard sites and vineyard management practices for optimum fruit quality. The university has developed environmentally sound pest and disease management techniques and is helping unlock the chemical mysteries of wine flavor profiles.
“In addition to discussing the science that goes into growing great grapes and making premium wine, I’ll talk about what I see as some of the major issues facing this rapidly growing industry,” Henick-Kling said. “I’ll also give an update on WSU’s vision for the Wine Science Center, a world-class facility that will help ensure that Washington wine continues to grow in market share and in prestige in the global marketplace.”
Henick-Kling has been director of the WSU viticulture and enology program since February 2009. Before moving to Australia in 2007 to become director of the National Wine Industry Centre, he was a wine researcher and educator at Cornell University for 20 years. He was instrumental in establishing Cornell’s undergraduate program in enology and viticulture and in developing the program’s focus on premium Rieslings. His research has long focused on the basics of fermentation science: the yeasts and bacteria that convert sugars and acids into alcohol, aroma, flavor, and rich mouthfeel. His research has contributed to the fundamental understanding of biological processes that enable winemakers to turn good grapes into great wine.
The Innovators lecture series highlights WSU research achievements and promotes informed discussion about matters of vital importance in the twenty-first century. Through lectures and panel discussions by faculty experts and industry leaders, WSU explores a variety of topics and inspires new visions for a vibrant future.