The craze is real, the trend is undeniable. Over the past ten years, more and more winemakers and drinkers have been immersing bottles to increase their lifespan and make them better. In the sea, in lakes or rivers. In France, such operations were carried out in Saint-Malo, Corsica, or in the Arcachon Basin, on Lake Geneva and under the Padirac ditch in the Cahors region, to name a few examples. In March 2021, 1000 bottles of Roussanne wine were also recovered from the frozen depths of Lake Tignes – using a helicopter! – where they lived for a year.

physical chemistry of beverages

According to cases and evidence, submerged wines will be silkier, more fleshy, fresher, sometimes more expressive, sometimes mellow… better, in any case, than a wine kept in the cellar in the classical manner. And therefore more expensive, it goes without saying, the concept clearly attracted the barge. The idea is as tempting as it sounds, but what exactly is it? How does time spent underwater affect the taste experience and physico-chemistry of beverages?

300 bottles of Crementa

To find out, the city of Colmar – the capital of Alsace wines – has embarked on a new project involving several research laboratories. On October 19, 2021, it immersed 300 bottles of crme (from Domaine Murray) beneath the Colmar-Hausen nautical base at a depth of 25 metres. By setting the following objectives: “Which components of a wine are modified by immersion compared to cellar aging, and how do these modifications evolve over time? Can we associate changes in the composition of immersed wines with differences during tasting?”“

The crme selected for this operation comes from the d’Alsace Moor estate. This is a main 2019 vintage with reserve wines from the previous vintage (2017-2018)

best attendant in the world

Before the immersion, Serge Dubs, host of a starred restaurant (L’Auberge de l’Ile in Ilhucerne) and in 1989 the world’s best sommelier, tasted three of these bottles blindly. “Beautiful luster, several bubbles at the same time alert but dynamic, fine, regular, persistent without being too jittery, which spread well over the surface of the wine … beads of bubbles that rise in number and regularly to the surface. Glass … offers a subtle fruit, floral and spring bouquet“, he said in particular, more details are being recorded here. The whole point is to know how this appreciation will develop over the next ten years. Every two years, batches of bottles will actually be withdrawn from the water So that they can taste again. Master. But above all they are analyzed by scientists (physicists, chemists, biochemists) from the National Research Institute for Agriculture (Inera Grand Est-Colmar Center), University of Haute-Alsace (UHA) and Reims Champagne – Will be done by scientists of Arden University.

physicist specializing in pupil phenomenon

“This is the first time, to my knowledge, scientific studies will be conducted to characterize the effects of underwater aging sparkling wines”, notes physicist Gérard Liger-Belair, an expert in champagne and sparkling wine at the University of Reims Champagne-Arden, who will participate in the research with his colleague, Clara Cylindre. In 2015, a consortium of scientists definitively analyzed a hundred bottles of champagne found five years earlier in the wreck of a ship … which sank in the Baltic Sea early 19.^I century! Bottles exclusively from the house of Veuve Clicquot, personally produced and marketed by Madame Clicquot. Thus they lived for 170 years under the sea at a depth of 50 meters and a constant temperature of 4 °C.

Physicist Gérard Liger-Belair heads the Effervescence, Champagne and Applications team at the University of Reims Champagne-Ardenne.

Tobacco and leather flavor

However, these bottles have retained internal characteristics – in terms of alcohol, sugars, flavours, organic acids or glycerol. – Champagne Wines: “we are surprised To note that the champagne we tested was perfectly preserved in terms of both chemical composition and aroma“, announced in 2015, Philippe Jeandet, Professor of Food Biochemistry at the Faculty of Science of the University of Reims Champagne-Arden. “I kept the aroma in my mouth for a long time. It tasted like tobacco and leather.“, the researcher specified, also the merits of this wine “Very small with a lot of freshness“. In early 2011, a bottle of this very old drink was sold at auction for 30,000 euros! And in 2014, even before the results of scientific analysis, the House of Veuve Clicquot dropped 350 bottles to 42 meters deep in the Baltic Sea The trend was started.

Found in a wreck at the bottom of the Baltic Sea, 170-year-old bottles were analyzed in 2015 by a consortium of researchers.

Under water, conditions are very different

Amazing and very informative because he 19 . also disclosed valuable information on the composition of champagne at the beginning of^I The results published in Century, 2015, however, did not give any real indication on the improvement of alcoholism. Without early bottles, scientists could not make any comparisons between cellar and underwater aging. Hence the importance of the experiments that have just started in Colmar. “Aging under water should obviously prompt a certain number of modifications because the conditions of preservation are very different from those of a basement”, emphasizes Gerard Liger-Belair.

essential role of oxygen

Under water, darkness is total and the pressure is high. The temperature is also cooler, which reduces the dynamics of the reaction mechanism when working inside the vials. But the main difference relates to the environment and gas exchange. The carbon dioxide from sparkling wine can certainly leak through the micropores of the cork much less than the bottles. But unlike what happens in the basement, atmospheric gases (oxygen and nitrogen) cannot pass into submerged bottles. Nitrogen is chemically neutral for its part, especially oxygen, which gives rise to oxidation reactions. However, for still wines as sparkling drinks, it is oxygen that plays a fundamental role in the aging process.

everyone agree

“Most of the evidence confirms that the old wine under water is improved by it. But this is perhaps a preponderance associated with the formal and very extravagant character of such immersion. Obtained by a combination of analytical instruments and tasting sessions Only objective results, will put all in agreement and make it possible to decide on the various developments of wines immersed or aged in the cellar.“, Gérard Liger-Belair estimates. His team will thus measure the evolution of the foamability of both wines immersed and aged in the cellar, as well as the amount of carbon dioxide dissolved in the bottles. This parameter is actually the size, the speed and the dynamics of bursting of bubbles that themselves release fragrance under the noses of consumers.

Hundreds of molecules to be analyzed

Using state-of-the-art equipment, in particular mass spectroscopy, researchers from InRai and UHA will analyze the evolution of molecular structure: volatile molecules likely to participate in organoleptic experimentation, but also hundreds of soluble components that define complexity. and the molecular landscape of wine. All of these developments will, in the end, be correlated with the appreciation of Serge Dubs and other oenologists. “If one lot is preferred over anotherhandjob We can objectify it and try to understand what happened at the molecular level“, introduces Gerard Liger-Belair. So the first verdict is expected in 2023.