Funky fermentation makes for an unusual cheese and wine pairing

Boozy fermentation leaves leftover cheese

Scientists and gourmands alike have been fascinated by the recent discovery of a 3,600-year-old cheese sample from a tomb in what is now the Xinjiang Uygur region in northwestern China (Cell 2024, DOI: 10.1016/j.cell.2024.08.008). This sample of kefir cheese is the oldest cheese ever discovered and the product of “kind of a funky microbial coagulation,” says Paul Kindstedt, a professor emeritus at the University of Vermont and cheese historian.

Kindstedt isn’t affiliated with the discovery, but he has a theory about why kefir cheese specifically was found in this tomb. It’s rooted in the unique biochemistry underlying kefir cheese’s production.

Solid, mild-tasting kefir cheese is a by-product of making liquid kefir, a fermented milk beverage you can find today in many grocery stores. Kefir is made via lactic acid fermentation of milk, in this case goat milk, thanks to the activity of a little microbe called Lactobacillus kefiranofaciens.

“There’s lots of lactobacilli in cheeses and milk products,” Kindstedt tells Newscripts, “but this one is unusual in that it produces an exopolysaccharide, glucogalactan. So it’s glucose and galactose in polymer form. It creates very sticky biofilms and a matrix of polysaccharide that then entraps the lactobacillus and yeasts like Saccharomyces.”

Many lactic acid bacteria ferment both glucose and galactose monomers into lactose, but L. kefiranofaciens ferments only glucose, leaving the galactose behind, Kindtstedt says. “If there’s enough yeast in the neighborhood, that galactose can then be fermented to produce carbon dioxide and alcohol.”

Alcohol was historically hard to come by on the Eurasian steppe where the cheese sample was found; it can be a hostile environment for agriculture and has little in the way of fermentable carbohydrates, according to Kindstedt. So making the alcoholic kefir beverage would have been one of the few ways locals could catch a buzz. That leads Kindstedt to ask, “Were these pastoralists in Xinjiang making kefir cheese deliberately, or was it just a by-product of the kefir beverage? That’s the funky question.”

Merlot overboard!

In other fermentation news, a trend in wine-making has been making waves online, thanks to the spread of a viral video. The video claims to show the sale of a bottle of wine recovered from the Titanic, but what it really shows is a bottle of wine produced by a craft winery that ages its wine underwater, out at sea.

Undersea wine-aging is banned in the US because of sanitary concerns, but that hasn’t stopped wineries elsewhere from submerging their sauvignons. The theory is that the wine is protected from ultraviolete light deep underwater and that the motion of the ocean brings out a unique flavor profile.

You can expect to pay a premium, sometimes hundreds of dollars per bottle, for this specialty wine, often sold adorned with the crusty remnants from the process. But does this aging process actually result in a noticeable difference in taste?

Two papers released in the past year investigated the chemical compositions of wines aged underwater and compared them with traditional cellar-aged wines. One paper, published in European Food Research and Technology, found that one underwater-aged wine had “significantly increased concentrations of naringenin and myricetin,” polyphenols associated with citrusy and bitter tastes, respectively (2023, DOI: 10.1007/s00217-023-04410-x). The other paper, published in Foods, found significant differences in the concentrations of several phenols but no difference in the wines’ fundamental characteristics (2024, DOI: 10.3390/foods13121812).

For what it’s worth, this Newscriptster will be saving his money and sticking to the occasional gin and tonic for the foreseeable future.

Please send comments and suggestions to newscripts@acs.org.