Sample of Grand Cru incomparable to Scotch (4)
I believe the answer is:
ruin
'scotch' is the definition.
(I've seen this before)
'sample of grand cru incomparable' is the wordplay.
'sample of' indicates a hidden word (I've seen this in other clues).
'RUIN' can be found hidden inside 'grand cru incomparable'.
'to' acts as a link.
(Other definitions for ruin that I've seen before include "Physical collapse" , "Destruction or bankruptcy" , "Disaster, collapse" , "Complete collapse or destruction" , "Defeat" .)