Perverse aversion to whisky (7,3,5)
I believe the answer is:
against the grain
'perverse' is the definition.
(both can mean unconventional)
I cannot understand how the remainder of the clue works.
(Other definitions for against the grain that I've seen before include "hostile to principles?" , "not for a malt whisky drinker" , "Joiners sometimes saw this" , "Following the difficult route" , "Out of character" .)