Fermentation was a process by which a substance became alcoholic over a period of time.
In 2285, Leonard McCoy dismissed the 2283 vintage of the illegal Romulan ale he had brought James T. Kirk by saying it took a while to ferment. (Star Trek II: The Wrath of Khan)
In 2374, Kathryn Janeway asked Neelix not to age his fruit compote in root nectar as long this time, as she became lightheaded after eating it at Prixin last year. (VOY: "Mortal Coil")