The chemical processes that create wine and make it unique. Wine is simply grape juice that has been allowed to ferment and undergo chemical changes. Wine can be made from fruit other than grapes, but these only account for about 1% of all wines produced. Without chemistry, wine could not be smelled, tasted, or even created.

We are able to smell wine only because when we inhale, its molecules travel through the air to the rear of the nose; a chemical reaction occurs, and the brain tells us what we are smelling.

Wine is created by a combination of chemical processes. The sun's warmth increases the sugar content in grapes, and this sugar provides a food source for the yeast. In the fermentation process the yeast convert the sugar into alcohol, which is followed by another chemical process, "malolactic fermentation". Lactic-acid bacteria in the wine produce enzymes that break down the malic acid into lactic acid and carbon dioxide. This second process is both discouraged and desired, depending on the region and the characteristics desired in the wine; excess fermentation can result in a dull wine with "off" odours.

The process of "fining" clarifies the wine by adding an element to the wine to absorb, move, or chemically react with sediment to remove it. The main element used today is a type of clay called bentonite.