1. The leaves of the vine absorb carbon dioxide from the atmosphere. The roots absorb water from the soil. These raw materials are converted into sugars by means of photosynthesis. The sugars are stored in the vine's grapes.
2. At this point the grapes are picked. The sugars are then converted into alcohol by the process of fermentation. Fermentation is kick-started by yeast, which is present in the atmoshere, on the skins of grapes and - in a winemaking context - absorbed into the walls, ceilings and surfaces of a winery.
3. Eventually - long after most wine would hopefully have been drunk - the wine will be attacked by bacteria and will turn into vinegar.
4. The vinegar will itself decompose, releasing carbon dioxide into the atmosphere.5. The cycle starts all over again!
