Port initially judged acceptable as wine (5)
I believe the answer is:
rioja
'wine' is the definition.
(I know that Rioja is a type of red wine)
'port initially judged acceptable' is the wordplay.
'port' becomes 'rio' (Rio de Janeiro is a port).
'initially' indicates taking the first letters.
The first letters of 'judged acceptable' is 'ja'.
'rio'+'ja'='RIOJA'
'as' acts as a link.
(Other definitions for rioja that I've seen before include "Spanish drink" , "Dry red wine from Spain" , "Wine from northern Spain" , "Spanish wine type" , "Spanish red wine" .)