Submerging bottles of wine in the ocean to age them may seem unusualbut, given that it has proved to be an effective technique, one might wonder why it isn’t used more often.

Away from the shore and shallow water, the ocean is quite temperate, even in tropical seas.

Shipwrecks – most famously the Titanic – are often found to contain bottles of wine that sur­vived the sinking. In 2010, a wreck discovered at a depth of 50 metres in the Baltic Sea, just off the Åland Islands, in Finland, yielded 168 bottles of champagne. The bottles were more than 170 years old and a close inspection of the corks (most of the labels had long since eroded) showed that the wines were from the houses of Veuve Clicquot Ponsardin, Heidsieck and Juglar. Incredibly, the contents were still drinkable, the depth having provided the wine with the perfect, constant low temperature.

Inspired to try new ways of ageing wines, Michel Drappier, of Champagne Drappier, first experi­mented in the Alps. This proved unsuc­cess­ful because high altitude sped up the ageing process, raising the pressure inside the bottle higher than the surrounding environ­ment, resulting in fewer bubbles in the champagne.

Drappier deduced that the ideal depth under the sea would be where the water pressure was equal to the pressure inside the bottle (five to six atmospheres) as there would be no stress on the cork and contents. He found the perfect spot in St Malo bay, in Brittany, France, about 30 metres down, where there is no sunlight and the water has a median temperature of 10 degrees Celsius – the same as his cellars in Champagne.

I was able to compare two of Drappier’s Carte d’Or champagnes, one from his immersion project and the other from his cellars, both of which had been aged for the same amount of time before release.

The Carte d’Or Immersion bottle was distinct­ive, with its barnacle-encrusted appearance and salt-crusted cork. A sniff of the champagne offered a medley of ripe white peaches and cherries, tart nectarines and brioche. A sip showed lively bubbles on the palate and more of that vivid, fresh fruit. The traditionally aged Carte d’Or was a lovely drop; it, too, had a similar nose of white peaches and tart nectarines along with some green apple, but the brioche notes were more pronounced and the bubbles were not as lively.

Ageing under the sea is a novelty for now but, with no electricity required, it could come to be considered a more sustainable technique.