Turning pistachios into culture (14)
I believe the answer is:
sophistication
'culture' is the definition.
(thesaurus)
'turning pistachios into' is the wordplay.
'turning' indicates anagramming the letters.
'pistachios'+'into'='pistachiosinto'
'pistachiosinto' anagrammed gives 'SOPHISTICATION'.
(Other definitions for sophistication that I've seen before include "Polish" , "Fashionable refinement" .)