The 'Coral Wine' Project Revolutionizes Wine Aging in a Marine Environment.

The Key Points of Coral Wines

Aging Environment: 
Before the "Coral Wine" project, the Adriatic Shell company was primarily focused on mussel and oyster production, and it still produces food today, but in the meantime, the main focus has shifted to wine.

Producing food in the same place where we age the wine means that on a weekly basis, we collaborate with an oceanography institute that takes sea samples to check for impurities and a veterinary institute that performs laboratory testing on mussel meat to ensure food quality. This implies rigorous scientific testing of the environment in which the bottles age.

Thanks to the underwater infrastructure, harmonious with nature in a sustainable way, wildlife has been restored in the valley and is flourishing with flora and fauna, as well as many small fish hiding from both predators and fishermen.

The so-called corals that form on the bottles are mostly small worms that clean the sea bottom and attempt to turn foreign objects into stone. This biodiversity in our cellar enables us to produce state-of-the-art bottle designs. In the past, labels were removed from the bottles, but recently, a technique has been developed to keep them and let the corals grow on top. 

The wine aging environment is both perfect and imperfect at the same time. On one side, the bottles age in the absence of light, complete silence, and constant temperature, and on the other side, they are exposed to constant sea pressure and vibrations from sea currents. Instead of minimizing the impact, special cages have been developed that allow the bottles to float in the sea with minimal contact with the holders, ensuring that the sea flows between the bottles and maximizes exposure to these conditions. They are also slightly elevated from the sea bottom, ensuring that the bottles do not take on unpleasant smells. Each cage holds 150 bottles, and currently, there are around 130 of them in the sea.

After submerging, the bottles are not left to themselves for extended periods, but we perform regular control dives to ensure that everything is in order. Sample bottles are taken out of the cages and closely monitored for changes in taste, smell, and quality. Sample bottles are often taken for laboratory analysis and compared with the original bottles for further research and development.

Aging Depth and Duration:
Not all wines age at the same depths, nor do we age them for the same period. Depths generally range from 25 to 40 meters. Aging time can be anywhere from 6 months to 5 years. For shorter periods, we choose lesser depths, and for longer aging periods, we choose greater depths to avoid temperature changes during summer and winter. Not all wines have the ability to be aged for the same time, even traditionally. A simple white wine cannot age as long as a Barolo from a quality producer. This holds true for underwater wines as well. Wines with a long shelf life change slowly. While we need to let the corals grow, we also need to change the wine enough so that it smells and tastes different but shouldn't tire it out or wear it down. Naturally, we will age Chablis, Gavi, Barbera, and wines with a shorter lifespan for a shorter time, and age Barolos, Amarones, and Riojas for a longer time.

Differences in Wines: These unique conditions of underwater aging cause the wines to differ from bottles aged in a traditional way. The constant stress causes the wines to be a bit more advanced in terms of development and seem older than they are. For instance, if you compared the same two wines from the same vintage, and one was aged under the sea, the first one would show more primary aromas and characteristics, and the second would display more secondary and tertiary aromas. The acidity would slightly mellow down, and the tannins (if there are any) would become slightly rounder. After laboratory tests, we discovered a significant drop in Calcium content in underwater cellared wines. All of these changes are best shown while tasting both wines side by side.

Underwater Aging Requirements:
Not all wines can successfully age underwater. Some wines flourish, and some wines fall apart below the sea. The first requirement is perfect microbiological stability. If there are any technical problems with the wines, underwater aging is prone to enhance them, causing the wine to be undrinkable.

Oxidative aging always helps the wine age underwater, as reductive winemaking turns the wines unpredictable; they can develop both well and poorly. High acidity and tannins help the wine endure the stress, and the structure is of great importance. Wines with a firm structure and a good balance are less likely to disintegrate and almost guaranteed to bloom underwater.

The Process of Selecting Wines for the Project:
With time, we found out that for the wine to be successfully aged below the sea, it needs to have a big potential for aging in a traditional way. High acidity, good structure, and quality tannins (tannins that will polymerize with time, not stay green). As abstract as this may seem, wines need to have a clear direction. Tasting and aging thousands of different wines have taught us that some grapes and appellations age better than others. Barbera and Nebbiolo age wonderfully, as well as Valpolicella and Amarone. We are having great success with Riesling, but it’s not on the market yet. When we choose the wine that is going to be aged under the sea, first we decide on the appellation. When we were choosing a Rioja for our portfolio, I personally went to Spain and tasted around a hundred different Riojas. Then, I picked out 20 best wines and ordered the samples. We wrapped all of the sample bottles in aluminum foil and held a blind tasting for a panel of 7 wine experts - sommeliers, wine bloggers, porters, etc. Finally, we settled on a few best wines. Marko always has the last word, as he picks the wines he feels will represent his project best.