Uncorking A Mystery


Chemistry major with one of his research subjects, a bottle of cabernet sauvignon. Frenchi is working on a project to document the chemical effects of oxidation on wine. Jake Weber photos

Mike Frenchi, '08, Explores Oxidation and Wine 

Albion College chemistry major Mike Frenchi joins the ranks of 21st-century researchers taking new looks at what is possibly the world’s oldest chemical experiment. “No, I don’t drink the samples,” Frenchi laughs. “But it’s not an unreasonable question, as Frenchi is spending this summer opening bottle after bottle of wine.

Under the supervision of Albion chemistry professor Vanessa McCaffrey, Frenchi applies state-of-the-art laboratory techniques in trying to find out exactly what’s going on in that bottle once it’s opened. “A lot of research is done during fermentation,” says Frenchi. “But we found hardly any research on wine after it’s been made. With so many people interested in the health benefits of wine, it will be interesting to know how opening the bottle affects the wine."

The project is straightforward, with a very practical basis. Under various storage conditions, Frenchi is tracking the chemical changes that occur when wine is exposed to oxygen. “We sample each bottle once a day for five days,” Frenchi explains, “because each bottle contains around five glasses of wine.”

The sample bottles are kept either room temperature or chilled, and corked with their original corks or a synthetic cork. Some bottles are further sealed with consumer products that employ a vacuum pump, or inert gasses, such as argon or nitrogen, to “reseal” the bottle. “When you open a bottle of wine, oxygen rushes in,” says Frenchi. “Oxidation is what actually spoils the wine.”

To determine the amount of oxidation that takes place, Frenchi monitors each bottle, each day, for pH changes (acidity) and sulfur dioxide concentrations (a naturally-occurring antioxidant and food preservative). After these determinations have been made, Frenchi then analyzes each sample using ultraviolet/visible spectroscopy to determine phenol concentrations (phenols are largely responsible for a wine's flavor and color) and color density of the wine. Further, each sample's chemical components are measured on a molecular level, through gas chromatography and mass spectroscopy. (GC/MS)

"These changes in GC/MS readings may help us understand how the presence of oxygen, may change chemical compounds in the wine," notes Frenchi. "It's pretty complicated, but we are using internal standards to see if the data will be reproducible." Reproduction of data, Frenchi notes, provides more precise detail on how oxygen may change wine, regardless of any specific wine's unique blend of chemical compounds.

“This study will likely be beneficial to both winemakers and wine enthusiasts. Hopefully this study will also expand the current knowledge regarding the potential health benefits of red wine consumption,” Frenchi concluded. “Many different studies have shown that drinking a glass of red wine every day will lower your risk for heart disease and may even help in preventing Alzheimer's , Parkinson's, cancer, and cavities, among other benefits. We hope that determining the various chemical interactions within an opened bottle of wine will provide more insight and enable further research to be conducted regarding these health benefits.”