Historic Beer 1843 was developed from a brew that spent more than a hundred and seventy years at the bottom of the Baltic Sea. PHOTOGRAPH BY JACKSON KRULE

In the summer of 2010, Christian Ekström, a diver from the Åland Islands, an autonomous region of around sixty-five hundred isles off of Finland’s west coast, began searching for a shipwreck in the Baltic Sea, based on a tip he’d received from a fisherman. The Baltic’s temperature is unusually consistent (between about thirty-nine and forty-three degrees Fahrenheit* on its seabed), and it has a salinity level that is less than a fifth that of oceans. Its coastal waters are also treacherously shallow. All of this makes it particularly well suited to sinking ships, and then, once they’ve sunk, to preserving them for centuries. (Creatures commonly known to erode wrecks, like shipworms, can’t survive in such brackish waters.) As a result, the Baltic has an estimated hundred thousand shipwrecks, only a fraction of which have been explored.

Ekström and his dive partners soon found a small, wooden schooner, a hundred and fifty-five feet underwater, coated in sand and algae. Its hull had ruptured and there were no name signs or ship bells by which to identify it. Shining his headlamp into the large gash in the ship, Ekström saw some dark-green bottles, lying corked among broken planks of mossy wood. He reached in and pulled one free.

As he rose to the surface with the bottle, the cork began to work its way out. He pushed it in with his thumb. Back on the boat, it popped out completely. “All this aroma came through,” he told me recently. “It was phenomenal. And we tasted it without any knowledge of what we were drinking.”

When he returned to the main island, Åland (pronounced Oah-land), Ekström began researching the mystery liquid, hoping it would also hold clues to the wreck. A wine expert he consulted guessed that it was very old champagne, and estimated that, if it tasted as good as Ekström believed it did, each bottle would be worth up to fifty thousand euros. “That’s when I started getting a little sick, because I recognized that we had been drinking eighteen thousand euros of champagne from the bottle and coffee cups,” Ekström said.

Later testing determined that it was indeed champagne, and that it had been bottled in 1839 or 1840, making it older than any previously discovered preserved champagne. Unlike the ship, the bottle bore a marking. Burned into the cork was an anchor—the logos of two champagne houses, Juglar, which is now defunct, and Veuve Clicquot, which was established in 1772. (At one point, Ekström called Veuve Clicquot and explained his discovery to a senior figure in the company. He recalls the man saying, “It’s a lovely story, Mr. Ekström, but where is Åland? I have heard of Holland and Poland and Scotland, but never Åland.”)

Ekström and his team continued to search the ship, diving twice a day for three weeks and retrieving a hundred and sixty-seven more bottles of champagne, along with spices, olives, and preserved fruits. About halfway through the search, Ekström came across five dark-brown bottles, squatter than the ones that held champagne. Back on the boat, one of the bottles cracked, spilling fizzing, yellow liquid onto his fingers. He tasted it and noticed flavors of tobacco, wheat, and “a lot of egg.” It wasn’t pleasant, but it was familiar. Ekström recalls thinking, “I don’t care about the champagne now. We just found the golden ticket—we found beer!”

In addition to diving, Ekström runs a gastropub attached to Stallhagen, a small brewery on Åland. Jan Wennström, the brewery’s C.E.O., told me that as soon as Ekström found the beers, Stallhagen was determined to reproduce them. At a hundred and seventy years old, they were the oldest preserved beers ever discovered, and the fact that they had been bottled indicated that they were of very high quality. (Beer in that era was normally stored in wooden kegs.) The Finnish government and an independent research institute took samples from two of the bottles for physicochemical analysis, a process that involved four years and a variety of methods, including gas chromatography and flame atomic-absorption spectrophotometry. Stallhagen secured exclusive rights to the results of the research.

The scientists’ report showed that saltwater had seeped in through the corks of both bottles. All of the yeast cells were dead, but some bacteria were still alive, which accounted for the fizz that Ekström had noticed. (According to Wennström, this finding has become a source of interest to scientists throughout the food industry. “They can’t understand how it’s possible that the bacteria lived for one hundred and seventy years,” he said.)

Although the beers in bottles were similar, the report noted that one was “more strongly hopped than the other,” suggesting that Ekström had come across an extremely old mixed pack. (There also appears to be a third type of beer among the remaining three, a darker variety, which Stallhagen hopes to analyze in the future.) The two beers smelled of “burnt rubber, over-ripe cheese, and goat,” flavors that Brian Gibson, a senior scientist who worked on the report, told me are likely a result of living underwater for so long. Beer is inherently unstable, he said, especially beer produced before the advent of pasteurization and other preservation processes. DNA analysis of the yeasts determined that, at the time the two beers were produced, they would have had notes of sweet apple, rose, butterscotch, and clove. They would have tasted sweet, too, as they had been fortified with sugar, similar to a Lambic, their closest modern-day analogue.

After receiving the analysis, Stallhagen contacted the Leuven Institute for Beer Research, in Belgium, to reverse-engineer the two varieties. Brewing typically involves only a few ingredients: barley, hops, water, and yeast (although Belgian and some other brewers frequently add other ingredients, like fruit, spices, or sugar). As Burkhard Bilger wrote for the magazine, in 2008, historically, “Yeast was left off the list because brewers didn’t know it existed; beer was naturally fermented, like sourdough bread.” This traditional mixed-yeast, or spontaneous, fermentation allowed for the presence not only of microbes that flavored the beer but also ones that spoiled it; hence the smell of burnt rubber, cheese, and goat. In light of modern brewing science, the Finnish team was in a relatively luxurious position: it could choose only the flavor-producing yeast. “It’s a little bit of an oxymoron, but it’s kind of a controlled spontaneous fermentation,” Wennström said.

Stallhagen and the Institute ultimately brewed, fermented, and bottled fifteen test beers over two years, before settling on two recipes. The brew that matched the hoppier of the original beers became Historic Beer 1842, which Stallhagen released in October, 2014, in a limited run of two thousand hand-blown glass replicas of the original bottles. Each bottle cost around a hundred and thirty dollars, but the brewery quickly sold out. The second, smoother beer, called Historic Beer 1843, was released in May, 2014. It is sold commercially throughout Finland and abroad for close to six dollars a bottle, though not yet in the U.S.

Earlier this month, Wennström sent me a few bottles of Historic Beer 1843. Late one Friday, I gathered a group of testers, who ranged from novice to connoisseur, in a small conference room at The New Yorker’s offices, in lower Manhattan, overlooking a baseball field framed by two high-rises. We drank from an assortment of glass, ceramic, and paper mugs.