[News] The treasure hidden in the beer bottles of a ship sunk 120 years ago

[Warlock-]

"BBC"

 

 

 

As the diver carefully passed one of the hatches into the sunken hold, he could see the treasure from the shipwreck that awaited him. It had been there for over 100 years. But now part of that treasure was about to emerge from the depths of the sea. The explorer, Steve Hickman, a dive technician and hobby diver, carried a small net bag with him. The treasure he was looking for was beer.

 

Preserved in the hold of this ship, there were rows of glass bottles with beer, partially buried in the sea mud.

 

As soon as the first bottle moved, the sediment churned and formed huge clouds. Hickman went blind. But he knew this wreck well: he had visited it several times before. So he went on, feeling for more bottles in the gloom. After bagging some, he left, and his team carefully brought the bottles to the surface. The wreck was the Wallachia, a freighter that sank in 1895 off the Scottish coast after colliding with another ship in heavy fog. The Wallachia had just left Glasgow, Scotland, and was packed with various types of cargo, including large containers of a chemical called tin chloride. But the ship also had thousands of bottles of alcoholic beverages on board. Many of those bottles were preserved in the icy waters of the seabed, where the ship remained for more than a century. Since diving into the Wallachia in the 1980s, Hickman has recovered dozens of bottles containing whiskey, gin and beer. But his recent visit, a teamwork with several dive buddies, led to something unusual.

 

"Resurrect" yeast

 

The recovered bottles were handed over to scientists at a research firm called Brewlab, who together with colleagues from the University of Sunderland in the UK, managed to extract live yeast from the liquid inside three of them. That yeast was used in an attempt to recreate the original beer. In 2018, a similar attempt in Tasmania had used yeast from 220-year-old beer bottles found in a shipwreck to recreate an 18th-century drink. However, the Wallachia yeast study revealed a surprise. Those beers contained an unusual type of yeast, and the team behind the work is now evaluating whether that long-lost strain could be applied in modern brewing, even to improve them.

 

This is just one example of a growing field of research among brewers and other beverage fermenters looking for forgotten strains of yeast, in the hope that they can be put to good use. That means hunting them in bottles found in shipwrecks, scrubbing old pots, and collecting samples from dilapidated distilleries where there may still be fabulous varieties. This kind of search is called bioprospecting, and "resurrecting" historic yeasts could have a number of applications, from cleaning up contamination to helping produce scents for the perfume industry.

 

"The most atrocious smell"

 

Hickman recalls that when he began collecting beer bottles from the Wallachia in the 1980s, it was still (almost) drinkable. He and his friends brought the bottles home and poured them into glasses. Remember that the drink, almost 100 years old then, slowly settled down and developed a thick, creamy head, almost like Guinness beer. But that's where the magic came. "It had the most atrocious smell," says Hickman. "Kind of a putrid, salty smell. I think that would be the best description." The taste, he adds, wasn't much better either. The bottles had other surprises, including the fact that they exploded, Hickman says. As they adjusted to the lower pressure above sea level, the gases inside the vessels expanded, sometimes breaking the glass. Hickman once left a bottle on the kitchen table of his parents' home and it exploded while they were in another room, spraying stinky, rotting beer everywhere. It took a long time to clean it, remember. Now the beer has deteriorated even more ... and he wouldn't even try to drink it. In general, drinking old beverages may be unsafe because it is not known whether they contain harmful bacteria or chemicals. However, some of Hickman's dive buddies were able to sample fresh beer created by Brewlab using yeast strains isolated from old Wallachia bottles. Andy Pilley, an amateur surveyor and diver who participated in the expedition to collect beer from the shipwreck, is one of those who tasted the result: a 7.5% alcoholic black beer. "I felt coffee and chocolate," he says.

 

"Time Capsules"

 

Yeast diversification could benefit all types of industries. For example, it could help perfume manufacturers create better fragrances. Yeasts are sometimes used to produce the complex chemicals of a flavor when they cannot be easily obtained from other ingredients. In recent years, genetically modified yeasts have become available on a scale for use in commercial production. Among the pioneers in this approach is the synthetic biology company Ginkgo Bioworks in the USA. Thomas notes that the Debaryomyces yeast found in Wallachia beer also appears to be tolerant of heavy metals like arsenic and lead. That may mean that it would be a good bioremediation yeast, used to absorb pollutants in an environment, to clean it.

 

Groundwater contaminated with arsenic has been linked to health problems in places like the west coast of South America, the Middle East or India, says Thomas. Pharmaceutical companies could also benefit from bioprospected yeasts. Many medicines are made with the help of yeast used to grow certain chemicals. Some suggest that even more efficient yeasts for this purpose could be found in the environment, perhaps in the sea. In addition, bread makers could turn to new yeasts - in fact, old ones - in the quest to diversify their products. In 2020, Seamus Blackley, the creator of the original Xbox video game console, announced that he had recreated Egyptian bread using yeast cultures extracted from ancient Egyptian baking containers.

 

Two scientists who assisted Blackley in his task are still researching Egyptian yeast strains and analyzing the genetic makeup of the yeast used in that experiment, in order to find out what contribution ancient strains may have made to bread. Blackley says the team intends to launch a more extensive DNA sampling program, in order to analyze other artifacts and archaeological sites.

 

But because it's something alive in an ever-changing environment, it's hard to know for sure whether a strain of yeast drawn from nature really is directly descended from one used in historic food production, says Caiti Smukowski Heil of State University. of North Carolina, in the USA. That's one of the reasons shipwrecks are so special, he points out: If you manage to extract the yeast from a sealed bottle that has been in dark, cold and stable conditions for many years, you can be sure that you have recovered the original yeast. used to make that product. Either way, he says, there is a "huge diversity of untapped yeast." Commercial bakeries, for example, rely heavily on standard strains of Saccharomyces cerevisiae.

 

But wild yeasts or historical strains that have been discontinued might be better options for modern production. "Yeast species outside of Saccharomyces cerevisiae are usually more tolerant of things like using frozen dough and sometimes even have a higher leavening ability," says Heil. Thomas says he wants to sample and study yeast from sealed containers in other shipwrecks or "time capsules" of well-preserved beverages. And by studying the genetics of ancient yeast strains, previously unknown but desirable genes can also be identified, which will influence genetically modified yeast in the future. But the Wallachia shipwreck is a reminder of how lucky we are to have access to a handful of historical yeast that we can safely associate with a specific time and place. In the nearly 30 years since Hickman dived there, he has witnessed the wreck deteriorate over time.

 

The structures and walkways above and around the engine room have collapsed. The cracks in the ship's aged walls widened. The boat disintegrates. "Possibly within the next 20 to 30 years, it will disappear completely," he says. The Wallachia is likely to take away the remaining beer bottles as it slowly melts to the bottom of the sea. A valuable connection to the brewers of the 19th century will be gone forever, taking with it the precious yeasts that are in forgotten bottles.