Italian winemakers move vineyards uphill to confront climate change

Wine producers and researchers in Italy are turning to new vineyard and cellar techniques to respond to climate change, rising alcohol levels in wine and declining soil health, themes that took center stage at the 79th Assoenologi Congress held in recent days in Conegliano, in the hills of the Conegliano Valdobbiadene Prosecco Superiore DOCG area.

At the meeting, scientists and technical experts described how warming temperatures are changing grape growing across northern Italy and much of Europe. Michele Faralli of the University of Trento said data collected in Trentino from 1986 to 2022 show a clear rise in annual and seasonal temperatures, especially in winter and spring. He said budbreak and flowering now occur up to 10 days earlier than they did in the 1980s, speeding up the vine’s cycle and increasing exposure to late frosts and heat stress.

Faralli said those shifts are affecting both yield and wine style. Grapes are ripening faster, acidity is falling and aromatic profiles are changing. In extreme years, some traditional varieties also face water and heat stress that can reduce production. He linked those local findings to broader international research, including assessments by the Intergovernmental Panel on Climate Change, which has reported average global warming of about 1.1°C above preindustrial levels.

One visible response has been a move uphill. Faralli said that between 2001 and 2021 vineyards in Trentino migrated toward higher elevations, with lower areas below 600 meters seeing abandonment while plantings increased above 800 meters. He said growers are also adapting through varietal choice, genetic selection and agronomic practices such as shading, emergency irrigation and soil management aimed at limiting climate stress.

Climate pressure is also reshaping decisions inside wineries. Viviana Corich, a professor in the Department of Agronomy at the University of Padua, said hotter conditions are causing earlier grape ripening and stronger sugar accumulation, producing musts with very high alcohol potential and wines that often exceed 14% to 15% alcohol. At the same time, she said, consumers are paying closer attention to health concerns tied to alcohol consumption and showing more interest in lighter, fresher wines with lower alcohol levels, as well as nonalcoholic products.

Corich said one microbiological approach involves using non-Saccharomyces yeasts, and in some cases less fermentatively efficient strains within the Saccharomyces group, so that not every gram of sugar is converted into ethanol during fermentation. By combining Saccharomyces cerevisiae with non-Saccharomyces yeasts, producers can reduce alcohol by about 1% to 2%, and in some cases by as much as 3%, she said. She added that yeast alone cannot solve the problem when a sharp reduction is needed, but it can work alongside enzymatic and physical methods that remove sugar and therefore alcohol. She also said non-Saccharomyces yeasts may add interesting varietal and fermentation aromas.

Researchers are also looking at future tools that do not rely on traditional genetic modification. Corich pointed to laboratory adaptive evolution as one route for selecting yeasts with lower alcohol yields without using genetically modified organisms. She also referred to microbial consortia used in some “proxy wine” products, including kombucha-based beverages, as possible inspiration for new products with a stronger health positioning.

Another major topic at the congress was the development of new grapevine varieties and clones through assisted evolution techniques, known in Italy as Tea and more broadly in the European Union as new genomic techniques. Riccardo Velasco, former head of Crea-Ve and recently appointed director general of the Edmund Mach Foundation in San Michele all’Adige, said European approval of the new framework is at an advanced stage after months of debate among the European Parliament, Council and Commission.

According to Velasco’s account of the preliminary agreement under discussion, the proposed rules distinguish between two categories. Category 1 covers plants with minimal genetic changes comparable to spontaneous mutations found in nature. Under the initial agreement, those plants would not be treated as genetically modified organisms and would not face consumer labeling or traceability requirements, though nurseries and farmers would still need technical information about what they are buying. Category 2 would include plants with more significant genetic changes and would remain subject to traceability and authorization rules similar to those applied to traditional GMOs.

Velasco said current authorizations concern only Category 1 techniques based on targeted mutagenesis without stable insertion of foreign DNA. In those plants, he said, no external DNA remains in the final sequence because the protein used for mutagenesis is degraded by the cell. That means the resulting vines are genetic clones of original varieties with mutations comparable to natural ones. By contrast, Category 2 techniques such as cisgenesis may leave minimal traces of external DNA and therefore require labeling and traceability.

He said future European regulation will need to define tolerance thresholds and precise criteria for separating those categories. He also warned that commercial protection could become complicated because Tea Category 1 clones may be difficult to defend legally as new plant varieties if they are treated as equivalent to natural mutations. In that case, he said, patent protection rather than plant variety rights may become more important, while club-style commercialization systems and DNA fingerprinting could help preserve exclusivity.

Soil degradation was another focus of discussion. Lorenzo Furlan of Veneto Agricoltura said sustainable practices applied together can improve soil quality and support carbon accumulation, but results take time. He pointed to precision agriculture and advanced management models that allow farmers to supply crops with what they need at each stage while reducing waste and environmental impact. He also stressed diversified crop rotations as a way to increase biodiversity and system stability.

Drawing on trials conducted by Veneto Agricoltura, Furlan said natural carbon retention in soil is slow. Over seven years, he said, progress was minimal. To speed recovery of soil sustainability, he said his organization combines basic conservation practices with additions of quality organic matter and measures that stimulate beneficial microflora able to fix nutrients and improve fertility. Compost, manure, properly managed slurry and treated organic materials can all help rebuild soil structure, he said.

He also cited modern agroforestry systems as a practical example. Combining trees with herbaceous crops on farms can produce more biomass sustainably, he said. Veneto Agricoltura has developed a project covering 600 hectares in which land is divided into homogeneous zones managed under both conventional and conservation systems so results can be compared over several years.

The discussions in Conegliano showed how one of Europe’s oldest agricultural sectors is trying to adapt on several fronts at once: moving vineyards higher as temperatures rise, changing fermentation methods to curb alcohol levels, testing new genomic tools for vine breeding and rebuilding soils whose organic matter has been depleted after years of pressure from intensive farming practices.