Long-forgotten yeast strains are being sought out from shipwrecks, abandoned breweries and other locations in the hope they could be put to good use if resurrected.
The wreck was the “Wallachia“, a cargo ship that sank in 1895 off the Scottish coast following a collision with another vessel in heavy fog. The “Wallachia” had just departed from Glasgow and was packed with various kinds of cargo. But the ship also had thousands of bottles of alcoholic beverages aboard. Many of them have been preserved in the cold water where the ship lay on the silty seabed for more than a century.
The diver Hickman has retrieved dozens of bottles containing whisky, gin and beer. But his recent visit, a team effort with several companion divers, led to something unusual. The bottles they retrieved were handed to scientists at a research firm called Brewlab, who, along with colleagues from the University of Sunderland, were able to extract live yeast from the liquid inside three of the bottles from “Wallachia”. They then used that yeast in an attempt to recreate the original beer.
In 2018, a similar project in Tasmania used yeast from 220-year-old beer bottles found on a shipwreck to approximate a beverage from the 1700s. But the study of the “Wallachia” yeast revealed a surprise. Those beers contained an unusual type of yeast and the team behind the work is now evaluating whether this long-lost strain could have applications in modern brewing or could even improve beers today.
The bottles had other surprises – including a habit of exploding, says Hickman. As they adjusted to the lower pressure above sea level, gases inside the vessels expanded, occasionally shattering the glass. Once, Hickman left a bottle on the kitchen table in his parents’ house. It burst while they were in another room, spraying stinking, decaying beer everywhere. It took a long time to clean up, he remembers.
“We opened it in containment level two laboratory conditions,” a Scientist says. This involved unsealing the bottles in a special cabinet filled with sterile air, in order to protect the scientists from any possible pathogens in the beer. This measure also ensured that the samples did not become contaminated with any modern–day yeast strains.
Genetic testing revealed that the “Wallachia” stout contained two different types of yeast – Brettanomyces and Debaryomyces. In a paper about the work, Thomas and his colleagues explain that it’s unusual to find Debaryomyces in an historic beer, though this type of yeast has turned up in a few Belgian beers made using spontaneous fermentation, which relies on leaving pre-fermented liquid open to the environment, so that yeast strains may settle on it.
This idea, that historic yeasts can impart heritage as well as interesting flavours, is catching on outside of the beer world. Alan Bishop has the title of alchemist and lead distiller at Spirits of French Lick, a distillery in Indiana, in the US. The company makes a range of boutique spirits, including bourbon, apple brandy, rum and gin.