(Yesterday's Enterprise) The prune juice scene is such a classic TNG moment. It would seem that it would become a part of Worf forever, but I can't remember ever seeing him drink prune juice again. Did he?
Worf is seen drinking prune juice on five separate occasions in the official Trek Canon; once on Star Trek : TNG and four times on Star Trek : DS9
He is initially introduced to the drink by Guinan in the TNG episode 'Yesterday's Enterprise'.
He orders "Chilled prune juice" at Quark's bar and in the mess hall of the USS Defiant in the DS9 episodes 'The Way of the Warrior' and 'The Quickening" and an "Extra large prune juice" in the DS9 episodes 'To the Death' and 'Let He Who Is Without Sin...'
His love of prune juice is also mentioned by other characters in two episodes; TNG 'Family' and DS9 'Rules of Engagement'