On the north coast of Tenerife, Bodegas Monje has embraced a distinctive approach to winemaking by aging some of its red wines beneath the Atlantic Ocean. Located in El Sauzal with a backdrop of Mount Teide, the winery submerges bottles nearly 18 meters underwater for a period of five to six months, then compares them directly against identical bottles aged on land.

This unconventional practice, known as underwater wine aging, has been gaining attention since 2009, when Italian winemaker Piero Lugano of Bisson submerged thousands of bottles of sparkling wine off the coast of Portofino. Inspired by stories of ancient wines recovered from shipwrecks, winemakers in various regions, including the Basque Country and the British Virgin Islands, have experimented with similar techniques. Proponents argue that factors such as ocean currents, near-total darkness, and the gentle, constant motion of seawater influence the wine’s maturation in ways traditional cellars cannot replicate.

At Bodegas Monje, the variety aged underwater is Tradicional Submarino, a red wine produced from local grapes cultivated in volcanic soil. After retrieval, bottles aged underwater are opened alongside counterparts stored in the winery to facilitate side-by-side tastings. This comparative approach aims to discern any sensory differences attributable to the marine environment.

Tasting sessions reveal noticeable contrasts between the two versions. The land-aged wine exhibits expected characteristics of dark fruit and firm tannins, while the underwater-aged counterpart tends to present a softer profile with a relaxed fruitiness and an occasional subtle saline note. Some tasters describe the ocean-aged wine as "silkier" or rounder, although questions remain as to whether these impressions arise from genuine chemical changes or sensory suggestion.

Research led by Associate Professor Angela Zinnai of the University of Pisa seeks to clarify the scientific basis for these differences. Studying underwater aging since 2018, Zinnai’s multidisciplinary group has combined chemical analysis with sensory evaluations to assess whether the ocean environment distinctively affects wine composition. Their findings indicate that submerged bottles exist in a relatively isolated microenvironment, where factors like oxygen content and the cyclical temperature variations of seawater play significant roles. Underwater aging may enhance the wine’s structural fullness and reduce oxidation, preserving aromatic qualities more effectively than conventional aging.

However, Zinnai cautions that not all wines benefit equally from underwater aging, and the method requires precise understanding of each wine’s characteristics and appropriate conditions. She warns against the indiscriminate submersion of wines without such knowledge, emphasizing that the practice is more than a trend only when grounded in scientific insight.

While underwater aging remains a niche within the winemaking world, wineries like Bodegas Monje continue to explore its potential. Visitors to the estate can participate in tastings comparing sea-aged wines to their land-aged siblings, an experience that combines sensory discovery with the dramatic setting of Tenerife’s volcanic coastline. The technique, often accompanied by visual appeal including barnacle-encrusted bottles and underwater footage, prompts ongoing debates about its value as a genuine innovation or an elaborate marketing spectacle.

For now, researchers continue to investigate how underwater conditions influence wine development, and consumers can assess for themselves whether the ocean adds a meaningful dimension to the glass.