Tea has long been linked to human health benefits like preventing cancer and heart disease. But with hundreds of chemical compounds hidden in tea leaves, it is unclear which substances have the strongest effects.

The slew of “healthy” chemicals in tea varies with the variety of plant, how and where it is grown, and how the leaves are processed. Even soil bacteria contribute to a plant’s chemical profile, including its color, taste and aroma.

“Tea has terroir, just like wine,” said Jacquelyn Gervay-Hague, a professor in the Department of Chemistry and affiliate researcher for the Global Tea Initiative for the Study of Tea Culture and Science at the UC Davis College of Letters and Science.

“Tea is exactly where the wine industry was 100 years ago in California,” she said.

For the California tea project, Gervay-Hague’s research group plans to develop tools and techniques to track naturally-occurring soil microbes at UC Agriculture and Natural Resources test plots in the Central Valley and Central Coast. The team will propagate their tea plants from decades-old shrubs growing at the UC Kearney Agricultural Research and Extension Center in Parlier, near Fresno. The plants at the Kearney Center date back to a 1967 research project funded by the Lipton Tea Company.

“I’m not a microbial person, I’m a chemist,” Gervay-Hague said. “However, if you know the chemical exchange that occurs between the plant and the environment, you can trace it back to the microbes.”

A leading expert in synthetic chemistry, Gervay-Hague has created immune-stimulating molecules called glycolipids for treating cancer and HIV. Glycolipids are also present in both tea and its associated microbes, she said. In the future, Gervay-Hague plans to expand into all aspects of tea, from growing and consuming tea to researching its health benefits. “This project has everything I love—tea, California and scientific challenges,” Gervay-Hague said.