All in all, there are three key factors that can affect the overall quality of a grape vine. These three are:
- slope; and,
Although these three reign supreme for quality, they would be nothing without their pimp, Photosynthesis. Photosynthesis is the conversion of light energy (sunlight) into chemical energy. The process transforms carbon dioxide (CO2) and water into sugars. The longer the vine has to photosynthesise, the higher the levels of sugars in the grape.
If the warmth from the soil or the sunlight is too high/low, then photosynthesis will stop! The plant will freak da f$%k out and go into shut-down mode. To keep photosynthesis ticking over and to maximize sugar content, optimal air temperatures are between 25-28°c.
Once we have all the required sugar in our grapes what happens next?
The grapes are picked (machine or hand) and bought into to be converted into vino! Once de-stemmed, crushed, pressed etc. the newly formed GrapeJuice is ready for fermentation.
Yeast, whether wild or cultivated, is now added to freshly squeezed grape juice (rich and heavy with it's oh so delectable sugars). These two baby mommas do a little dance and fermentation begins.
Fermentation is basically like a year 6 formal. There are two forces at play which decide the fate of your reputation. One is metabolism (transformation), and the other is catabolism (destruction). On one side of the room, there is pubescent change (metabolism) which sees you and Stacey Michaels smooching and sliding into first. On the other side, it's not so pretty, Derek Hutchinson is dancing by himself to Spandau Ballet's True, destroying any hope of high school Baller status...the holy grail so desperately craved.
Just like real life, fermentation is cruel and unfair, one force cannot happen without the other. For the humble, naive grape juice, the destruction (catabolism - Derek) of sugar and the transformation (metabolism - Stacey) is crucial to creating the by-products of ethanol, CO2 as well as that home run...wine.