AJEV Study Weighs the Economics of Adapting Winegrape Production to Extreme Heat

New research finds no single right answer: staying the course, investing in shade technology and switching cultivars each pay off best under different heat scenarios.

DAVIS, Calif., [August 28, 2026] – As winegrape growers contend with more frequent and severe heat events, a study published in the American Journal of Enology and Viticulture (AJEV) offers growers a practical economic framework for one of the industry’s most consequential questions: When does it make financial sense to adapt, and how?

The study, “Economics of Winegrape Adaptation: Technology Adoption, Cultivar Selection, or Migration,” compares three strategies for managing heat-related risk in winegrape production: installing shade cloth to protect fruit from direct sun, switching to a more heat-tolerant grape variety, or moving production to a cooler growing region. Using Cabernet Sauvignon production in Napa County as its case study, the research team built a financial model to estimate long-term returns for each strategy and paired it with a consumer survey to gauge how buyers might respond to the resulting changes in variety, region and production practice.

The findings show that the best strategy depends on how severe the heat becomes. Under mild temperature effects, continuing to grow Cabernet Sauvignon in Napa County without any changes remained the most profitable path. As heat events grow more frequent and damaging, at a modest level, the economics tipped in favor of shade cloth. Under the most extreme heat scenario modeled, switching to a heat-tolerant variety – the study used Carignane as its example – produced the strongest financial return. Migrating production to a cooler region, modeled as a shift from Napa County to Lake County, trailed the other strategies across every scenario tested in the study.

That distinction matters for an industry built on decades-long investments in vineyards, grape varieties and regional identity.

“Extreme heat is no longer a once-in-a-decade problem for winegrape growers,” said Kristen Barnhisel, ASEV President and winemaker for J. Lohr Vineyards & Wines. “Research like this is exactly why AJEV exists: to take real vineyard and market data and turn it into something a grower can actually use to make informed decisions. We are glad to see it getting this kind of attention that it deserves.”

The study’s authors, Bradley J. Rickard, Justine E. Vanden Heuvel, and  Alex M. Susskind of Cornell University, and Yu Ping Chang of Penn State University, built a net present value model drawing on University of California Cooperative Extension cost-of-production data for Cabernet Sauvignon in Napa and Lake Counties and for Carignane in Napa County. The model accounted for establishment costs, ongoing production costs and revenues over a 30-year period under four climate scenarios ranging from no heat events to severe, recurring heat damage.

To understand how adaptation might affect what consumers are willing to pay, the researchers also surveyed 308 U.S. wine consumers in early 2024, yielding 303 usable responses after data quality checks. Participants who were told that shade technology was protecting the grapes from extreme heat indicated a willingness to pay about 17% more for the wine. A switch to a different, more heat-tolerant grape variety earned a roughly 12% premium when consumers understood it as a climate response, and moving production to a new region earned about an 11% premium. The researchers note in the study that these premiums may shrink over time as such practices become more common and modeled them as lasting only through the fifth to ninth years of full production.

The study has drawn notable attention since its publication in June 2026, with an Altmetric Attention Score of 117 as of August 11, 2026.

Its reach reflects the stakes involved: vineyard decisions about planting, infrastructure and location can shape a grower’s finances for decades, making the economics of climate adaptation an increasingly urgent consideration across the wine industry. The study offers a framework that growers and other stakeholders can adapt to their own costs, yields and prices to weigh these choices for themselves.

“Growers have always adapted to their site, but the pace of change now means those decisions carry real financial weight,” said Markus Keller, AJEV Science Editor and viticulture professor at Washington State University. “This study gives growers something they haven’t had before: a way to weigh technology, plant material and location against each other in dollar terms, not just growing conditions. That’s the kind of research AJEV exists to publish, work that starts in the field and ends up useful at the kitchen table.”

The study was published in Volume 77, Issue 1 of the American Journal of Enology and Viticulture (DOI: 10.5344/ajev.2026.25043). Read “Economics of Winegrape Adaptation: Technology Adoption, Cultivar Selection, or Migration” at ajevonline.org.

About the American Journal of Enology and Viticulture

First published in 1950, the American Journal of Enology and Viticulture (AJEV) is the official journal of the American Society for Enology and Viticulture (ASEV) and the premier English-language publication dedicated to scientific research on winemaking and grapegrowing. AJEV publishes full-length research reports, reviews, insights, technical reports and letters on topics spanning wine chemistry, sensory science, process engineering, wine quality assessment, microbiology, methods development, plant pathogenesis, grape diseases and pests, rootstock and clonal evaluation, field practices, and grape genetics and breeding. All papers are peer reviewed, and authorship is open to researchers regardless of ASEV membership. As of January 2025, AJEV publishes under a full open-access model, making all new content freely available to readers worldwide. Learn more at ajevonline.org.

About the American Society for Enology and Viticulture

Founded in 1950, the American Society for Enology and Viticulture (ASEV) is a 501(c)(6) tax-exempt professional society dedicated to the interests of enologists, viticulturists and others in the fields of wine and grape research and production worldwide. ASEV’s membership includes professionals from wineries, vineyards, academic institutions and organizations, and the Society counts roughly 1,000 members and 50 Industrial Affiliates, along with Eastern U.S. and Japan chapters. ASEV publishes the American Journal of Enology and Viticulture (AJEV) and hosts the ASEV National Conference each June and, with the California Association of Winegrape Growers, the Unified Wine & Grape Symposium each January. In February 2023, ASEV created the American Society for Enology and Viticulture Foundation, a separate 501(c)(3) nonprofit, to engage in charitable and educational activities, including scholarships for enology and viticulture students. Learn more at asev.org and asevfoundation.org.