What is wine made of?

~85% water 

Sometimes less if the other compounds are more.

~10 to 15% Alcohol

Principally ethanol, but includes a whole range. Formed by the yeast consuming the sugars. Higher alcohols are also in wine, called Fusel oils, formed from sugars or amino acids, which have a higher molecular weight than ethanol due to at least one more carbon atom. 

Other than making you tipsy they add to the aromatic effect of the wine.

~4 to 10% glyserol

A colorless, odorless, polyol compound, not quite as sweet as sucrose. Sauternes can be 20% glyserol!

~0.1 to 3% sugar

White wine usually has less than red.

~0.4 to 1% Acids

Without acids wines would taste bland and be terrible. All these acids are partly why one can get acid indigestion from too much wine. Dominant are sour malic, sharp tartric acids, and fresh citric acid. 

Creamy lactic and succinic acid both form during alcoholic fermentation. Lactic acid is also formed along with bitter sour malic acid via malolactic fermentation. 

Other acids include acetic (sour vinegar),

pyruvic (sour), sorbic, ascorbic, butyric, oxalic, propionic, glycolic, galacturonic, fumaric, mucic and a host of others.

Other small but vital bits!

Acetaldehyde, amino acids, proteins, tannins, minerals, hydroxycinnamates, anthocyanins, flavonols, proanthocyanidins and pyranoanthocyanins, vitisins, stilbenoids, oak lactones, damascenone, volatile thiols, norisoprenoids, terpenes, pyrazines, volatile phenols, TDN, (1,1,6,-trimethyl-1,2-dihydronapthalene), copper and even arsenic!

To learn more about these terms check

The Grape Gripe Wine Dictionary

or read Dr Andrew L. Waterhouse's wonderful page.