Saccharomyces cerevisiae is a pretty awesome yeast. It's one of the first that humans discovered, and is still used today in the creation of beer, wine, and bread. So, in other words, it's the foundation of human society. So, what role did wasps have in bringing us this delightful stuff?
Photo by Alex Wild.
What's interesting about S. cerevisiae is that young grapes don't have it, yet 25% of ripe, damaged grapes do. It also cannot be transmitted through the air, and can't survive cold winters on its own. With all that in mind, how did it become widespread enough to aid us so heavily in fermentation? According to research published in PNAS, it all comes down to social wasps.
What researchers discovered is that the yeast can survive in the stomachs of wasps. Not only that, but a queen can have it in her gut when she hibernates, and it will survive the autumn-to-spring sleep, and get passed on to offspring. These offspring then spread it around to fruits in the wild. Yup, the stuff spent months in a bug's gut. So it was thanks to a winter spent inside the wasps that natural fermentation was able to occur, and the predecessors to wine developed.
But the fun doesn't stop there. The researchers were also able to link the wasps to maintaining the same strain of yeast between the vineyard to the winery, meaning the same exact yeast variety stayed in one place, leading to specific and knowable fermentation.
The researchers linked specific isolated wasp strains to types of fermentation:
Ten wasp isolates were related to wine strains, three to a group of strains found in bread, one to a mixed group encompassing African beer, palm wine isolates and laboratory strains, and one to a group containing natural isolates found in African palm wines.
So next time you have a glass of wine, remember that the yeast that fermented it probably spent a winter in a wasp's stomach.