Cool storage important for bag-in-box wines
Wine researcher Helene Hopfer at the Robert Mondavi Institute for Wine and Food Science published her findings in the Journal of Agricultural and Food Chemistry. (Karin Higgins/UC Davis photo)
When it comes to wine, if you bag it and box it, you better keep it cool, advise researchers at the University of California, Davis.
In the most comprehensive study to date on how storage temperature affects wines with different packaging systems, UC Davis researchers found that bag-in-box wine is more vulnerable to warmer storage temperatures than bottled wine. Their findings are reported online in the American Chemical Society’s Journal of Agricultural and Food Chemistry.
“Earlier research has compared bottled wine with bagged wine or bottled wines capped with different closures, but this is the first comparison of all of the different packaging configurations under different storage temperatures,” said lead researcher Helene Hopfer, a postdoctoral scholar in the UC Davis Department of Viticulture and Enology.
“In addition, this was the most comprehensive wine packaging and storage study, examining the effects of temperature on aroma, taste, mouthfeel and color, and correlating those changes with measurements of chemical and physical changes,” said Hopfer, who collaborated on the study with enology professors Susan Ebeler and Hildegarde Heymann.
The researchers used chemical analyses and a panel of trained tasters to analyze how storage at three different temperatures affected California chardonnay in five different packaging configurations: glass bottles with either natural corks, synthetic corks or screw caps and two kinds of bag-in-box containers.
The wine was made from grapes grown in Monterey County and fermented in stainless steel tanks, rather than oak barrels.
The researchers found that warmer storage temperatures produced the most significant changes in the wine, and those changes were more pronounced in the bag-in-box wine than any of the bottled wine. Bagged wine stored at 68 and 104 degrees Fahrenheit aged significantly faster than did the bottled wine, becoming darker and developing sherry-like, dried fruit-like and vinegar-like attributes. Many of the observations made by members of the sensory panel who tasted the wine were confirmed by chemical analysis.
The researchers found that all of the wines analyzed aged better when they were stored at 50 degrees Fahrenheit.
“The way a wine looks, tastes and smells is affected by the way certain wine compounds react with oxygen,” Hopfer said. “Those reactions speed up at higher temperatures, so differences in the way packaging systems manage oxygen in the container become critically important to aging and stability of the wine.”
The researchers have conducted a very similar study using the same packaging configuration and storage temperatures with cabernet sauvignon wine. A paper reporting the results from that study has been submitted for journal publication.
Constellation Brands and ACI CORK USA provided wine samples and packaging materials.
About UC Davis
For more than 100 years, UC Davis has engaged in teaching, research and public service that matter to California and transform the world. Located close to the state capital, UC Davis has more than 33,000 students, more than 2,500 faculty and more than 21,000 staff, an annual research budget of nearly $750 million, a comprehensive health system and 13 specialized research centers. The university offers interdisciplinary graduate study and more than 100 undergraduate majors in four colleges — Agricultural and Environmental Sciences, Biological Sciences, Engineering, and Letters and Science. It also houses six professional schools — Education, Law, Management, Medicine, Veterinary Medicine and the Betty Irene Moore School of Nursing.
- Helene Hopfer, Viticulture and Enology, (530) 752-9356, [email protected]
- Susan Ebeler, Viticulture and Enology, (530) 752-0696, [email protected]
- Hildegarde Heymann, Viticulture and Enology, (530) 754-4816, [email protected]
- Pat Bailey, UC Davis News Service, (530) 752-9843, [email protected]