The flavors of caramelization. Heat transforms table sugar, a sweet, odorless, single kind of molecule, into hundreds of different molecules that generate a complex flavor and rich brown color. A few aromatic examples (clockwise from top left): alcohol, sherry-like acetaldehyde, vinegary acetic acid, buttery diacetyl, fruity ethyl acetate, nutty furan, solvent-like benzene, and to a sty maltol.