German's certainly after port and wine (5)
I believe the answer is:
rioja
'wine' is the definition.
(Rioja is an example)
'german's certainly after port' is the wordplay.
'german's certainly' becomes 'ja' ('yes' in German).
'after' says to put letters next to each other.
'port' becomes 'rio' (I've seen this before).
'ja' put after 'rio' is 'RIOJA'.
'and' acts as a link.
(Other definitions for rioja that I've seen before include "North Spanish wine" , "Dry red wine from Spain" , "kind of red" , "Wine from northern Spain" , "Open space (ancient Greek)" .)