Right, I single out a wine (8)
I believe the answer is:
riesling
'a wine' is the definition.
(I know that Riesling is a type of Rhenish)
'right i single out' is the wordplay.
'right' becomes 'r' (common abbreviation).
'out' indicates anagramming the letters (out can mean wrong or inaccurate).
'i'+'single'='isingle'
'isingle' anagrammed gives 'iesling'.
'r'+'iesling'='RIESLING'
(Other definitions for riesling that I've seen before include "Strange wine for Sir Ingle" , "Sir Ingle makes wine from this grape" , "Gin riles the wine" , "Dry white wine (German)" , "German/Austrian wine" .)