Some Western Carolina University chemistry students are hoping the fruits of their labor in a university laboratory will benefit Western North Carolina’s wine-making industry.
The students have been developing several types of instrumental analysis methods during the fall semester to determine how changing chemical compositions affect the sensory properties of wine, said Alesia Jennings, visiting assistant professor of chemistry and the students’ lab instructor.
The students traveled to Biltmore Winery at the Biltmore Estate in Asheville early in the fall semester to participate in a behind-the-scenes tour of wine production facilities. They now are focused on using their analysis methods to test samples obtained from the Biltmore winery and other wines purchased from area retailers. At the end of the semester, the students will prepare written reports and present their findings to the Biltmore vintners, Jennings said.
While at the winery, the students met with Sharon Fenchak, one of two master winemakers employed by Biltmore. She guided the class through the steps of the entire industrial wine-making process, including grape-tasting, harvesting and crushing, as well as fermentation, pressing, aging and bottling. At every step along the tour, Fenchak suggested chemically important issues that the students might attempt to solve in their laboratory course.
The students selected two general issues of the winemaking industry to address – developing an analysis procedure to determine the dissolved oxygen and sulfite concentrations during several stages of the wine-making process, and determining the chemical characteristics of various aroma and taste profiles of wines.
“Using techniques called molecular absorption spectroscopy and high-performance liquid chromatography, some students are determining the phenolic content of wines,” Jennings said. “Phenolics are a class of compounds that affect taste, color and mouth-feel of a particular wine. Commonly known phenolics include tannins, which have to do with ‘mouth feel,’ and anthrocyanins, which affect color. Other students are developing techniques to measure the flavor and aroma profile of a wine at various stages of the aging process using a technique known as headspace gas chromatography mass spectrometry.
“Another student group is examining the metal content of the vineyard soil using a technique called inductively coupled plasma optical emission spectroscopy for the potential application of understanding the transfer of metals from soil to grape to wine,” she said.
In every project, students are developing measurement procedures that utilize modern instrumentation housed in the laboratories of the Natural Sciences Building at WCU, as opposed to the more traditional wet-chemical analysis commonly utilized in the wine industry, Jennings said.
The students were joined on the introductory tour at Biltmore Winery by Jennings and two other WCU faculty members – Scott Huffman, associate professor of analytical chemistry; and James Cook, the Department of Chemistry and Physics’ instrumentation specialist.
“The students thoroughly enjoyed seeing chemistry in action,” said David Evanoff, department head and associate professor of analytical chemistry. “One student commented that she is now considering a career in winemaking because she was so impressed by the enthusiasm, knowledge and love for her job that Ms. Fenchak displayed.”
The off-campus collaboration is providing a unique occasion for the students to gain practical experience, Evanoff said. “I think this is a great example of the kind of regionally engaged education WCU students receive,” he said. “Rather than the cookie-cutter experience that a student might get from being handed a sample and following a list of instructions to analyze it, students in this lab have been given both the opportunity to solve a real-world problem and the freedom to develop their own solutions through open access to state-of-the-art instrumentation housed in the department.
“Regardless of the career path that these students take, the complex problem-solving and method development skills honed during this laboratory experience will prove invaluable.”