Assistant Cooperative Extension Specialist
Viticulture and Enology
Oberholster, an assistant Cooperative Extension specialist in the Department of Viticulture and Enology, specializes in wine chemistry. Oberholster completed her Ph.D. in wine chemistry at the University of Adelaide, South Australia. Oberholster was affiliated as a wine researcher with Stellenbosch University in South Africa for 10 years before joining the UC Davis faculty in 2011.
Climate change, sustainability, fruit and wine processing and wine quality, phenol chemistry, and mouth-feel
Climate change and its impact on water resources, temperatures, and light pose a challenge to the winemaking industry. New technologies can help the vine and wine industry implement sustainable practices. My research focuses on two areas. I examine how growing practices and environmental factors such as climate change influence grape ripening and composition. I also investigate the influence of different winemaking techniques on wine composition and quality. In both the vineyard and the winery, I explore alternatives to enhance sustainability of the industry.
- Berry tannin biosynthesis with ripening in Cabernet Sauvignon grapes in response to changes in environmental factors such as temperature and light.
- Investigation of the impact of mechanical harvesting and optical berry sorting on grape and wine quality.
- Manipulation of the phenolic profile extracted from grape skins during fermentation based on a fundamental understanding of the extraction kinetics.
- Investigation of the relation between optimal micro-oxygenation application and red wine composition.
- Influence of barrel maturation, wood alternatives, and micro-oxygenation on red wine aging and quality.
- Recovery and re-use of cleaning water in a winery: the use of alternative “green” cleansers for sanitizing wine microorganisms.
- Effects of winery wastewater on soil, grape nutrition, and juice and wine quality.