The perfect brew
Matthew T. Kerr spent his senior year at UNCW brewing gallons of tea he would never drink. The tea, from the local plant yaupon holly (historically referred to black drink when brewed by Southeastern Native Americans) is used in Kerr's research endeavors in residue analysis.
His research earned him the XXXVII National Lambda Alpha Award and the Jenkins Certificate for Distinguished Undergraduate Research from the Lambda Alpha Anthropology Honors Society before he graduated from UNCW and started the geography graduate program at University of Tennessee, Knoxville, where he continues to use the same research methods. His black drink studies continue at UNCW.
Yaupon holly is native to coastal Southeastern North America and was the only natural source of caffeine in the region prior to European contact. Kerr's research of black drink's lipid residue in clay pot sherds can be used to shed light on the cultural uses of black drink in prehistoric America and also to map where and when the drink was brewed using evidence from the archaeological record.
Black drink "was infamous in the anthropology department," says Kerr, and is known for its use in early Native American purging ceremonies since consuming large quantities of the tea may encourage vomiting. This history of black drink earned the plant its Latin name, Ilex vomitoria when the Europeans first witnessed such ceremonies.
Even students and faculty members outside the UNCW anthropology department might be more familiar with Yaupon Holly than they think. "It's grows right outside of Randall Library," Eleanora A. Reber says. She is the chair of the anthropology department and aided Kerr through his research.
Americans caffeine intake now comes from imported coffee and teas, but yaupon holly was a very common way to make tea until the early 1900s. It was local, free and packed the caffeine pick-me-up desired.
Before Kerr started his research, he and Reber knew there was a chance that the caffeine and other chemical elements of the brewed drink could be left behind in the unglazed pottery used by those who prepared and drank it. In order to find out, Kerr, under Reber's guidance, recreated the preparations of black drink in pottery he made himself.
Kerr brewed the tea in unglazed clay pottery like those used by early Native Americans, dumped the tea, broke the pottery and buried the sherds around North Carolina.
"Some of them were buried in my own backyard," says Reber, noting that her yard shows a lot of typical and ideal characteristics for how the southeastern shore of North Carolina would have acted then. After three months, Kerr and his team dug up the sherds and went to the lab to extract any data they could find.
Surprisingly, they found more than they expected.
Reber and Kerr both hypothesized they'd find some residue, but probably not of a type to be helpful. To their surprise, the caffeine from the yaupon holly leaves stayed in the unglazed sherds. This finding led Kerr and Reber to publish their findings entitled "The Persistence of Caffeine in Experimentally Produced Black Drink Residues" in the Journal of Archaeological Science and will be helpful in further anthropological studies including black drink as well as Native American archaeological studies.
In addition to the Lambda Alpha Award, Kerr is nominated for the 2012 National Collegiate Honors Council Portz Scholarship. His study is a "fine piece of research and deserves to win," says Reber. The two will continue to publish their findings as they continue to dig up sherds spread around North Carolina.
For those curious what black drink tastes like, Kerr wouldn't know.
"We never tasted it," says Kerr, noting Reber was pregnant at the time, and he was too "busy liking not vomiting."