A Tale of Wasps and Wine
Humans have been making wine for over eight thousand years – but have our least-loved insects been our secret collaborators since the very beginning?
The Invention of Wine
The earliest archaeological evidence of winemaking was found in modern-day Georgia, dating back to 6000BC or earlier. By 4000BC winemaking was practiced across West Asia and the Mediterranean. There are many stories, myths and legends describing the invention of wine. In the Old Testament, Noah is said to have cultivated the first vineyard and from it made the first wine shortly after the great flood. According to ancient Persian legend, wine was discovered by a member of the harem of the great King Jamshid seeking poison after losing the king’s favor. In Greek mythology, Dionysus is attributed with the invention of wine – one such myth says that after his lover Ampelus, a satyr, was struck down by the goddess Selene, he was reborn as a grape vine from which Dionysus made the first wine. But could the invention of wine be attributed not to any prophet, prince or god, but to the humble and hard-working wasp?
The Importance of Yeast
Fermentation, the process by which yeast or bacteria break down sugars and other carbohydrates, is essential to winemaking (as well as the production of other foodstuffs like bread, beer, yogurt, and kimchi). In wine production, Saccharomyces cerevisiae (aka Brewer’s Yeast) is most common, although many other strains of wild yeast can be present on harvested grapes and contribute to the fermentation process and the qualities of the finished product. These yeasts break down sugars, mainly glucose and fructose, producing alcohol and carbon dioxide. Traditionally winemaking would rely on wild yeast alone for fermentation, but most modern winemaking practices involve the use of commercial yeast strains with high acid and alcohol tolerances for more consistent and controllable results. Even so, the presence and composition of native wild yeast forms part of the “terroir” – the combination of soil, climate, environment, and other local factors which gives a wine its distinctive character.
Why Wasps?
But how is native yeast diversity maintained, and how are grapevines inoculated with these wild yeasts year after year? This is where wasps come in. Social wasps have been found to house living yeast populations within their gut. Overwintering wasps (the ones destined to found new colonies come spring) provide safe harbor for yeast strains to ride out the winter. The guts of these wasps provide not only shelter, but also a place for yeasts to mate, generating new strains and maintaining local diversity. Native wasps (along with some bee and fly species) may be responsible for the yearly reinoculation of grape vines. Researchers at the University of Florence have found that social wasp species are capable of transmitting yeast found in their guts to growing grapes. Contact with wasps altered the composition of yeast species found on harvested grapes, and even influenced the aromas found in the resulting wine through changes to the fermentation process. By feeding wasps food containing live yeast prior to release, researchers were able to introduce specific yeast strains to grape vines, demonstrating the potential for wasps to be used as a natural vector to transform or restore the vine mycobiota.
In Summary
Social wasps may have been crucial to early winemaking practices, shaping and maintaining local yeast diversity, and delivering the yeasts essential for fermentation. Native wasp species continue to support the maintenance of native yeasts and the generation of new diversity, as well as acting as a yeast delivery service. By performing these services, wasps help shape the local ‘terroir’, influencing the flavours and aromas of the wine made. By harnessing these processes, it may be possible for winemakers to restore native mycobiota, re-introducing favourable yeast strains to their vines with the power of wasps. Wasps have assisted us in our winemaking since the beginning, may have played a key role in traditional winemaking practices, and present exciting opportunities for future innovations in the world of wine.
Photo by Liubov Ilchuk on Unsplash