In 2010, divers found a sizable amount of alcohol—including 168 bottles of 170-year-old champagne—tucked away in a shipwreck on the bottom of the Baltic Sea. Two milliliters made it to the University of Reims Champagne-Ardenne in France, where biochemist Philippe Jeandet and his colleagues analyzed it and reported their findings in the Proceedings of the National Academy of Sciences.

Markings on the bottles dated the booze, but also told investigators where it came from. The remarkably old drink originated from three champagne houses: Veuve Clicquot Ponsardin, Heidsieck and Juglar. The former two still operate today.

Jeandet and his team found important clues in the champagne’s ingredients. According to Nature.com, the shipwreck’s location—just off the Finnish Åland archipelago—might suggest that the cargo was headed to Russia, but the bottles contained 300 grams of sugar per liter, half of what Russians were normally known to drink. Instead, it is theorized that the loot was going to Germany, where the civilians enjoyed a more modestly sweet drink. Regardless, this would be much sweeter than today’s champagne, which generally only has about 10 grams of sugar per liter.

The bottles also had higher concentrations of iron and copper than contemporary champagne, but a lower percentage of alcohol. Presence of wood tannins suggested that the bubbly was fermented in wooden barrels. The team also found low levels of acetic acid, which meant it had not spoiled.

In 2011, two of these bottles were auctioned off, one for a staggering €30,000 (then around $44,000). The money was given to fund marine archaeology scholarships. Eleven more were sold the following year, with the rest being stored in Åland.

So what did this ancient booze taste like? The paper explains:

At first, the Baltic samples were described using terms such as ‘animal notes,’ ‘wet hair,’ ‘reduction,’ and sometimes ‘cheesy.’ ‘Animal notes’ are unequivocally related to the presence of volatile phenols ... ‘wet hair’ descriptors were to be expected for a wine that had spent such a long time sheltered from any oxygen source, and they were justified by the presence of light sulfurous compounds such as hydrogen sulfide, methanethiol, and dimethyldisulfide ... Finally, the term ‘cheesy’ is related to butanoic and octanoic acids.

Fortunately, when given time to breathe, the champagne’s taste improved. Tasters used words like “grilled,” “spicy,” “smoky,” and “leathery” to describe the aromas.

Thanks to dark and cold conditions, the ocean served as an underwater wine cellar and kept the alcohol in excellent condition. “The identification of very specific flavor and aroma compounds points to a very complex product, like modern champagne, albeit having been altered somewhat,” Patrick McGovern, a biomolecular archaeologist at the University of Pennsylvania in Philadelphia, said. “Considering that these champagnes had been ‘aged underwater’ for 170 years, they were amazingly well preserved.”

In an effort to test out how champagne age underwater, 350 bottles of a newer vintage have been placed in the water. Every few years, tasters will unearth a bottle and compare it against an exact replica stored above ground to see how different conditions can affect the taste.

[h/t: Nature.com, Gizmodo.com]