Winemaking and grapegrowing have a Field day
UC Davis introduces extension enologist and showcases research facilities
Robert Mondavi Institute executive director Clare Hasler (left) meets the new University of California, Davis, Cooperative Extension enologist Dr. Anita Oberholster (right) at last week's Viticulture & Enology Field Day.
Davis, Calif.—The Viticulture & Enology Department at the University of California, Davis, hosted a field day May 13 to update the industry about department facilities, programs and extension resources—most notably, the introduction of a new cooperative extension enology specialist, Dr. Anita Oberholster.
Oberholster officially joined the faculty April 1. During last week’s field day at the Robert Mondavi Institute (RMI), Oberholster met winemakers, industry executives and UC Davis faculty colleagues. During her presentation, she told attendees, “I’m happy and privileged to be here. UC Davis is very well known in the wine industry worldwide.”
During the next several months on the job, Oberholster intends to visit the grape- and wine-producing counties within California and meet the respective cooperative extension farm advisors for each county. “I’m here to learn and listen, and I want to interact with as many people as possible in the California wine industry,” she said.
A native of South Africa, Oberholster obtained her undergraduate degree in chemistry and biochemistry from Stellenbosch University. Her Ph.D. studies were at the University of Adelaide in Australia. Much of her research focus has involved chemistry and analytical techniques to evaluate wine phenols, in particular analyzing polymeric pigment structure and composition during wine aging. Her doctoral thesis was titled, “Investigation of the Chemical and Sensory Properties of Red Wine Pigments.” Oberholster explained: “Polymeric pigments are important because they stabilize color, and they are important in their contributions to wine as it ages.”
Her studies in Australia included involvement in developing a “Mouth-feel Wheel” for red wine, patterned after Dr. Ann Noble’s “Wine Aroma Wheel.” She co-authored a paper with Australian researchers Richard Gawel and I. Leigh Francis called, “A ‘Mouth-feel Wheel’: Terminology for communicating the mouth-feel characteristics of red wine,” published in 2000 in the Australian Journal of Grape and Wine Research.
Oberholster explained that proanthocyanidins, a class of phenols, are an important contributor to astringency in wines. The mouthfeel study examined chemical and sensory attributes related to mouthfeel, primarily in Australian Shiraz, but also in several other red varietals. “There was a need for a vocabulary to describe changes in mouthfeel as wine ages,” Oberholster said. A later study, published in 2009, examined mouthfeel in white wines made with and without pomace contact and the additions of anthocyanins.
She interned with two of South Africa’s largest wine companies—Distell Group Limited and KWV. Since 2002, Oberholster has been a researcher in wine chemistry at Stellenbosch University’s Department of Viticulture and Oenology. Some of her recent work has included effects of micro-oxygenation before malolactic fermentation on Pinotage wine, research on the influence of fining and cross-flow micro-filtration on Pinotage wine; and the influence of commercial tannin additions on red wine phenol composition and quality. Regarding the latter study, she commented, “The results indicate that the addition of exogenous tannins can make a difference if the wine lacks phenolic structure, but if the wine already has good phenolic structure, additions won’t make much difference.”
As extension enologist, Oberholster’s duties include both research and extension/outreach assistance for the wine industry, and she plans to divide her time equally between both areas. Some topics she hopes to research at UC Davis include the effect of barrel maturation on wine aging and quality, and evaluating different cap management techniques for different varietals. She said she looks forward to working with the new UC Davis research winery’s state-of-the-art, small-scale fermentors that enable evaluation and measurement of multiple variables affecting wine composition and quality.
UC Extension past and future
Department of Viticulture and Enology professor Dr. Linda Bisson, whose duties in recent years have included enology extension in addition to her regular teaching and research activities, is perhaps more pleased than anyone to see Oberholster come onboard. Bisson said, “Anita is Christian’s replacement, a decade later,” referring to Dr. Christian Butzke, now an enology professor at Purdue University, who was the most recent cooperative extension enologist at UC Davis. The position had remained unfilled due to funding and staffing limitations, which Bisson elaborated upon when discussing “a new era in extension.”
Bisson explained that traditional state and federal funding sources for extension programs are expected to continue to decrease and completely run out by 2021. In preparation for the future, the department created its VENSource program for enology, designed to provide information transfer with a reliance on electronic media, but also include targeted cooperative extension programs that are stakeholder-driven and funded. Bisson emphasized, “Extension in the future is going to have to be stakeholder-funded as well as be efficient and accessible.”
One of the main extension tools is expected to be UC Davis’ new “Enology Access” website, enologyaccess.org, which continues to add content with practical guides, research, course content and industry resources. Bisson said the department will continue its series of “Wine Flavor 101” courses for the industry—funded by registration fees—and to expand online program and course offerings with webinars and tutorials. Bisson summarized, “VENSource will be f ocused on providing industry-targeted programs, in both live and online formats.”
Field day tours and talks
As part of the field day tours and talks, Teaching and Research Winery winemaker Chik Brenneman discussed plans for the new sustainable winery building, planned as an 8,000-square-foot facility adjacent to the new winery. “This facility is being designed to showcase sustainable technologies we think are important to the wine industry and to compare these technologies,” Brenneman said.
At the facility, new technologies will be evaluated, including carbon capture systems, water reuse and clean-in-place systems, as well as energy technologies such as fuel cells. Facility construction is being funded through a $3 million gift from the late Jess Jackson and his wife, Barbara Banke, plus $1 million in campus funds. Groundbreaking is expected by the end of 2011, with building occupancy planned for early 2013.
Dr. David Block discussed research capabilities in a tour of the new LEED Platinum teaching and research winery, focusing on the 152 small-scale research fermentors donated and designed by T.J. Rodgers, founder and CEO of Cypress Semiconductor Corporation of San Jose, and owner of 500-case Clos de la Tech Winery, San Carlos, Calif. The new fermentors include automated and programmable pump over devices, Brix meters, temperature sensors for monitoring and control, and wireless transfer of all data to a central computer to monitor and graph fermentations in real-time.
Professor Block said, “The goal here as a research winery is to have as much control as possible for our research projects, and to pilot new technologies that our students can take out into the commercial wine industry.”
Dr. Andy Walker, a professor and geneticist specializing in viticulture, and cooperative extension viticulture specialist Dr. Jim Wolpert discussed the 12.5-acre teaching and research vineyard adjacent to the RMI complex, its role in teaching viticulture to students and providing grapes for the teaching winery, and research projects under way and planned.