"wine is proof that God loves us." -Benjamin Franklin
The formula for wine: sugar + yeast = alcohol, Co2 and heat. It could not be any simpler. Out of this tiny equation springs forth a deep ocean of flavors and experiences. This natural process can and will occur with out mankind’s involvement; prompting the illuminated comment by Benjamin Franklin.
Yeast is all around us in the environment including the skins of grapes, as soon as the yeast comes into contact with the sugar inside the grapes it converts the natural sugars of the juice into alcohol, carbon dioxide and heat. A vat of fermenting grapes is ALIVE! It looks and feels alive to the touch. It is a very exciting to experience, to witness! Do yourself a favor and seek out the opportunity. After the carbon dioxide bubbles and the yeast have done their work what remains is WINE! (Or the winemaker traps the carbon dioxide in the wine for sparkling or method Champenoise. More on that later.)
(Note: While Fermentation will often occur naturally, many winemakers control the fermentation with cultured yeast.)
The wonderful marvel of this natural phenomenon is that we understand so much about it yet can not duplicate it artificially. As noted in the sub-section titled “WATER INTO WINE” in The Sotheby’s Wine Encyclopedia by Tom Stephenson “The individual flavoring elements in any wine represent barely two percent of its content. Although we can determine with great accuracy the amount and identity of 99 percent of these constituents, the mystery is that if we assembled them and added the requisite volume of water and alcohol, the result would taste nothing like wine, let alone like the specific wine we would be trying to imitate.” Did you catch that? Wine can NOT be made in a test tube!
Understanding this genesis of wine is key to loving wine and appreciating this beverage. It is magical and mystical the way so many varied flavor and taste experiences come from what are very basic ingredients; sugar + yeast = alcohol, Co2 and heat!
To learn more on the technical aspects of fermentation take a look at this great web site: http://www.winepros.org/wine101/enology.htm