Zinfandel Heritage Vineyard
An important component of the Department's Oakville Experimental station in the Napa Valley is The Zinfandel Heritage Vineyard. Described as a "vibrant museum of the zinfandel grape," the vineyard is an unprecedented collection of rare Zinfandel vine cuttings from all over California. Established in 1989 by a research team consisting of UC Davis' Prof. James Wolpert (Chair, Department of Viticulture and Enology), UC Extension Viticulturist Emeritus Amand Kasimatis and UC Extension Farm Advisors Ed Weber (Napa County), Rhonda Smith (Sonoma County), Glenn McGourty (Mendocino and Lake Counties), Donna Hirschfelt (Amador and El Dorado Counties), and Paul Verdegaal (San Joaquin County). The one-acre vineyard includes a total of 90 selections from 14 counties in California. The goal of the Heritage Vineyard, according to Jim Wolpert, is to "help [the industry] discover answers to some of the mysteries surrounding Zinfandel and to preserve the special qualities of the old vines for future generations." Not only is the Vineyard of tremendous historical and viticultural interest, it also has a special significance for the wine and grape growing industry because it represents a resource for future plantings of Zinfandel with a broad range of selections. Zinfandel Advocates and Producers (ZAP), a non-profit organization "dedicated to recognizing the uniqueness of the Zinfandel grape," has donated over $180,000 to the Heritage Vineyard since 1998, possibly the largest grant coming from an independent organization focused on one specific wine-grape varietal.
The selections were generally taken from vineyards 60 years old, but many were much older. The cuttings were specifically chosen by the team because the vineyard was known to produce unique, high-quality wines. However, it is not clear whether the grapes' uniqueness is due to the particular clone of Zinfandel or the site, climate, soil and cultural practices. These differences will become clearer now that the vines have been collected at one site and will be farmed under a uniform set of practices. "By following variables such as cluster weight, berry size and cluster tightness," Wolpert says, "we can determine which might be genetic and which are due to other factors."
"It is our responsibility as vineyardists, winemakers, craftsmen and 'keepers of the flame' that we seek out the purest and finest quality clones of Zinfandel in California, isolate them, nurture them, study them and then possibly make them available commercially on a large scale, all to insure that Zinfandel moves into the next millennium in its most superb incarnation," explains winemaker Kent Rosenblum.
The Vineyard has been planted and designed keeping in mind that it is both a repository of plant material and a collection of historic material. The vineyard is planted at a spacing of 9 ft x 8 ft (row x vine) in a gravelly Bale loam soil. St. George was used as the rootstock and the vines are head-trained and spur-pruned in the "goblet" shape, as they would have been in the nineteenth century. These practices are still in use today, since they ensure a low yield (of high quality). The Heritage Vineyard requires authenticity: "we need to replicate the conditions which have given Zinfandel its reputation," Wolpert explains. "Our use of St. George as the rootstock, nearly square spacing and head-trained spur-pruned vines supported only by stakes is a design much as you would have seen 100 years ago. One concession to modern viticulture was the installation of a subsurface drip irrigation system."
Zinfandel Advocates & Producers has overseen the production of wine from this unusual vineyard, and each year a Heritage Vineyard wine is previewed to attendees of the: An Evening With The Winemakers event ,during the annual ZAP Festival, and also sold during the Auction. The 2002 vintage was previewed at the Festival in 2004. "The Heritage Vineyard brings us all together as scientists, historians, farmers and artists," adds Rebecca Robinson, ZAP's Executive Director.
The 1997 Heritage Vineyard Zinfandel was made by Nils Venge of Saddleback Cellars, the 1998 by Robert Biale of Robert Biale Vineyards; the 1999 by Matt Cline formerly of Cline Cellars, the 2000 by Rod Berglund of Joseph Swan Vineyards; the 2001 by Joel Peterson of Ravenswood; the 2002 by Ehren Jordan of Turley Wine Cellars and the 2003 Heritage Vineyard Zinfandel by Paul Draper of Ridge Vineyards.
The Heritage Vineyard will establish a body of information about Zinfandel which will support the quality of Zinfandel grown in the future. "The quality of Zin will not be compromised," says winemaker Joel Peterson (Ravenswood), and Co-Chairman of the ZAP Heritage Vineyard Program. "We all base our winemaking on great fruit, and our goal in the Heritage Vineyard is to speed up the clock on research," he adds.
Mary Buckles Pisor, who helped make the 1997 Heritage Vineyard Zinfandel at Saddleback Cellars in Napa, says "the Vineyard is of tremendous historical and viticultural interest to those fascinated by Zinfandel. For the consumer, the Vineyard is a living history and it provides an easily accessible demonstration of where Zinfandel is really made---in the vineyard."