Patagonian Winemakers Confirm Underwater Aging Changes Wine’s Taste

A panel of ten leading winemakers from the Alto Valle region in Patagonia has confirmed that aging wine under the sea produces measurable sensory differences compared to traditional cellar storage. The finding follows a blind tasting held last week in Río Negro, where bottles aged in the underwater cellar off Las Grutas were compared with control wines stored on land. The event took place at the headquarters of the Río Negro Secretariat of Fruit Growing and brought together winemakers from some of the region’s most prominent wineries, including Horacio Bibiloni of Bodega Humberto Canale, Marcelo Miras of Bodega Miras, Ricardo Tello of Viñedos San Sebastián, María Eugenia Herrera of Rivera del Cuarzo, Catriel Rastrilla of Bodega Aonikenk, and Ricardo Hernández of Familia Dellanzo.

The wines evaluated were produced in 2024 and submerged in July 2025 at a depth of more than 10 meters in the San Matías Gulf. For the tasting, these bottles were compared with control samples from the same wineries, produced in 2023, 2022, and 2020 and stored under standard cellar conditions. The methodology included basic controls to reduce bias, such as removing visual cues and using only bottles that had not been exposed to the underwater environment.

Horacio Bibiloni, who acted as spokesperson for the group, stated that “there are notable differences” between the wines aged under the sea and those kept on land. According to Bibiloni, wines submerged for more than six months “feel different” and display characteristics similar to those found in wines aged for longer periods. He noted that “it seems as if it had spent more time aging, especially compared to last year’s wine.”

The bottles were placed in specially designed cages anchored to the seabed. Each bottle was sealed with wax before immersion to protect the corks and prevent saltwater from entering. This system allowed direct exposure to marine conditions without compromising the wine’s integrity.

One aspect that drew particular interest among the experts was the challenge of identifying a single factor responsible for the observed changes. Bibiloni admitted uncertainty about what exactly happens underwater but listed several possible influences: the gentle movement caused by tides, which keeps bottles in constant motion despite being anchored; water pressure at 10 meters depth, which is not considered extreme but may still play a role; and light exposure on the seabed, which can be greater than in many underground cellars.

Temperature is another key difference. While traditional cellars are typically kept around 15°C (59°F), water temperatures in the gulf reach about 19°C (66°F), potentially accelerating certain aspects of wine evolution. However, none of these factors alone fully explains the final result. “What cannot be measured or repeated enters into the realm of sensations,” said Bibiloni. He emphasized that “100% of those present at the tasting agreed there were changes in the underwater wine.”

For participating wineries, this experiment was seen as positive not only for its technical results but also for its commercial potential. “For wineries, this experience is very valuable because it results in a different wine,” summarized Bibiloni, who has nearly three decades of experience in winemaking.

The tasting included red blends and some Malbec batches. Other varieties such as Semillón—currently being aged underwater by Canale—were not part of this session. There are also ongoing experiments with sparkling wines, including one from Bodega Agrestis, which may be evaluated in future tastings.

The underwater cellar project now involves about 20 regional wineries and is becoming a distinctive feature within Argentina’s wine industry. Mariana Cerutti, director of Viticulture for Río Negro province, said that “the results are very positive and motivate us to continue deepening this innovative technique.” She highlighted that Río Negro has “the only underwater cellar in Argentina and Latin America with quality wines,” which helps differentiate local products and opens new opportunities for regional winemaking.

To further promote this initiative, an open tasting event will be held on Saturday evening at a restaurant on Las Grutas’ Seventh Descent beach access point. Organized by Río Negro’s Wine Route association and supported by provincial authorities, attendance will be limited and tickets available through official channels.

With unanimous support from regional experts, underwater aging is moving beyond experimental status to become a concrete tool for differentiation. In an increasingly competitive market, Patagonian wine now offers a technical and sensory distinction that strengthens its identity and broadens consumer experiences.