When Philippe Jeandet sampled what is probably the oldest champagne ever tasted, he was allowed just one droplet squirted from a microsyringe. Divers retrieved 168 bottles of the 170-year old champagne from the bottom of the Baltic Sea in 2010, but only 2 millilitres of the drink reached Jeandet's laboratory for analysis.

The small sample shows the that seabed preserved the champagne surprisingly well, and offers clues about nineteenth-century winemaking practices, says Jeandet, a biochemist at the University of Reims Champagne-Ardenne in France. He and colleagues report their findings on 20 April in the Proceedings of the National Academy of Sciences.1

The bottles were discovered in a shipwreck off the Åland archipelago, an autonomous region of Finland, and identified as early nineteenth-century by engravings on their corks. In 2011, a two were auctioned and one was sold for a record €30,000 (then US$44,000). The money went to fund scholarships in marine archaeology projects, says Björn Häggblom, a spokesperson for the government of Aland. Eleven more bottles were sold in 2012; the others are stored in Aland and may be auctioned later.

Quite a vintage

Although the shipwreck’s location might indicate the bottles were on a trade route to the Russian Empire, their sugar levels say otherwise. Russia usually consumed champagne with sugar content higher than 300 grams per litre, Jeandet says, but the shipwrecked bottles had less than half that, suggesting they may have been intended for German markets, which favoured moderately sweet wines. By present standards, this would be exceedingly sweet: the most popular style today, brut, uses about 10 grams per litre.

Compared to modern champagne, the Baltic samples had considerably higher concentrations of metals such as iron and copper, which may have been the result of using a higher proportion of taille — a lesser quality juice from the second pressing of the grapes. The ancient samples were also less alcoholic (around 9.5%) than modern equivalents (about 12%).

Chemicals revealing the presence of wood suggests alcoholic fermentation took place in barrels: a second fermentation of sharp-tasting malic acid into softer lactic acid likely occurred in the barrels as well, says Jeandet, but was not as closely controlled as it is today. That explains why the wine had a creamy or yoghurty quality, not common to today’s wines, he says; expert tasters described it as “cheesy”.

Smoky and leathery

The Baltic samples also elicited descriptions such as “animal notes” and “wet hair”. But a quick swirl in the glass to oxygenate the wine yielded more pleasant aromas, described as “grilled”, “spicy”, “smoky” and “leathery”. Dominique Demarville, who is in charge of the winemaking team at the champagne house Veuve Clicquot, tasted the champagne three times, and says that after a few minutes he detected ripe fruits, truffles, smoke and honey.

“The identification of very specific flavour and aroma compounds points to a very complex product, like modern champagne, albeit having been altered somewhat,”says Patrick McGovern, a biomolecular archaeologist at the University of Pennsylvania in Philadelphia. “Considering that these champagnes had been ‘aged underwater’for 170 years, they were amazingly well-preserved.”

The conditions in which the wine was found—near darkness at a constant temperature of 2–4°C—probably helped to preserve its aromas and taste, says Jeandet. Veuve Clicquot has now put 350 bottles of its own champagne on the seafloor, close to Silverskar Island in the Aland archipelago. Tasters intend to try some every three years and compare them with the progress of identical bottles stored in its own cellars, Demarville says.