Pass case of Rioja onto wine producer … (6)
I believe the answer is:
ravine
'pass' is the definition.
(thesaurus)
'case of rioja onto wine producer' is the wordplay.
'case of' says to hollow out the word (remove centre letters) (outsides of).
'onto' is a charade indicator (letters next to each other).
'wine producer' becomes 'vine'.
'rioja' with its middle removed is 'ra'.
'ra'+'vine'='RAVINE'
(Other definitions for ravine that I've seen before include "Vainer in narrow gorge" , "Defile" , "Steep-sided gorge" , "Deep narrow gorge between mountains" , "Type of gorge" .)