Muse for poets, lovers, and general good-timers for time immemorial, the joys of wine rest soundly on the workmanlike and heroic efforts of some of our smallest friends in the biome: yeast. Yeast are single-celled organisms, members of the Kingdom Animalia, and are ubiquitous in vineyards and on grapes.
Grapevines, through the miracle of photosynthesis, turn water and carbon dioxide into oxygen and little energy storage molecules called glucose. The vines store extra glucose in the grapes, making them sweet and delicious to birds and other animals who consume the grapes and scatter their seeds. However, in a well-tended vineyard, we pick the grapes before that can happen. Instead, we allow the yeast to feed on the sugars in the grape juice. The yeast digest the sugar and turn it into carbon dioxide, heat, and ethyl alcohol. We, in turn, consume the wine, and the alcohol, and it makes us dance better and tell funnier jokes. What a beautiful natural cycle.