Two scientific studies commissioned by the Livermore Valley Winegrowers Association show 12 identifiable growing districts within the 260,000-acre Livermore Valley American Viticultural Area (AVA).
Analyses of topography, soils and microclimates across the region also showed the majority can be better classified as a warm Region III, not a hot Region IV as many wine industry experts previously believed.
"Knowing that only 4,000 acres of the AVA are planted to grapevines, and that many of those acres are concentrated in one district, it may be that wine-making in the Livermore Valley AVA is still in its infancy," said Phil Wente, a fourth-generation winegrower at Wente Vineyards. "And that's after more than 160 years of history. Many distinct combinations of district, varietal, rootstock, viticultural and enological practices remain to be explored."
Wente led the effort to establish Livermore Valley as an AVA in 1982 and was instrumental in the recent project to define the 12 districts. Funding for the studies came from the California Department of Food and Agriculture.
Patrick Shabram Geographic Consulting of Loveland, Colo., drew the new districts based on a study of the Livermore Valley's soil and topography by Coastal Viticultural Consultants of Angwin, and Shabram's own study of meso-climate patterns of the valley.
The wine association is sharing the district concept to emphasize the diversity and potential of Livermore Valley.
"For years, growers and vintners have anecdotally talked about the differences between the far western side of the AVA and the eastern side, the differences between the valley floor and the hillsides, the variation in soils and the differences from one vineyard to another," Livermore Winegrowers executive director Chris Chandler said. "We've needed to get beyond anecdotes and general observations."
The new districts average 22,000 acres each and are defined by a combination of climate, soil, geology and slope. They have been named Tesla, Ruby Hill, Crane Ridge, Altamont, Mendenhall Springs, Vallecitos, Sunol, Palomares, San Ramon Valley, Mt. Diablo Highlands, Valle de Oro and Amador Valley.
Maps, a flyover video and materials describing each district are on the Livermore Valley Winegrowers Association website, www.lvwine.org/library.php.