The world's oldest champagne, bottled before Victoria became Queen, is still drinkable, with notes of "truffles and caramel", according to the experts.
An "addictive" bottle of 1825 Perrier-Jouet was opened at a ceremony attended by 12 of the world's top wine tasters.
Their verdict: the 184-year-old champagne tasted better than some of its younger counterparts.
There are now just two 1825 vintage bottles left - and Perrier-Jouet has no plans to open them soon.
The wine and champagne experts convened at the winemaker's cellars in Epernay in France, for a "once in a lifetime" tasting of the 1825 champagne - officially recognised by Guinness World Records as the world's oldest.
British wine writer John Stimpfig described the "reverential silence" as Perrier-Jouet cellar master Herve Deschamps eased out the cork, followed by a round of applause as the champagne was poured.
"It was a memorable evening, and tasting the wine was like tasting history in a bottle," he said.
As for the flavour of a wine bottled just 10 years after the battle of Waterloo, Mr Stimpfig said he drank it more out of curiosity than for pleasure.
He said: "The wine was heavily oxidised, with a sherry-like character.
"However I did taste notes of truffles, caramel and mushrooms.
"Most of the bubbles had disappeared, although there was a slight spritz left."
But Serena Sutcliffe, the head of Sotheby's international wine department, who helped organise the tasting event, described the wine as "addictive" with a complex flavour of figs and even a "slight nose of the sea".
She said: "What was interesting was that I preferred the 1825 champagne to later vintages we tasted, dating from 1846, 1848 and 1874."
She said each sip would have been worth "hundreds of pounds" if it had been sold at auction, but added: "It is virtually impossible to assign a value to the 1825 vintage - we've never seen anything like it on the market."
Wine tastes have changed over the past 184 years - the 1825 vintage was sweet, and even had a little brandy added at the "topping-up" stage.
But it was this very sweetness that experts believe helped the wine to survive for so long, together with the five to six atmospheres of pressure within the bottle.
"It's the bubbles that kept it younger," said Ms Sutcliffe.
She added there was no guarantee that the remaining two bottles of 1825 would be as drinkable as the one she and fellow experts sampled, to mark the release of a new Perrier-Jouet vintage.
"They could last for years, and they might be better or worse, " she said.
"At this age, wine tends to go its own way and a lot depends on the cork which in the case of the champagne we drank was in very good condition."
Mr Deschamps said Perrier-Jouet intended to keep the remaining two bottles for some years yet.
"I don't expect I will ever open another bottle like it," he said.
"That is a treat for the next generation."