Check on content of wine (4)
I believe the answer is:
rein
'check' is the definition.
(both can mean to control or limit)
'on content of wine' is the wordplay.
'on' becomes 're' ('on' can be mean 'with reference to').
'content of' says to take the centre.
The middle of 'wine' is 'in'.
're'+'in'='REIN'
(Other definitions for rein that I've seen before include "Horse controller" , "Part of tack" , "Restriction" , "leading article?" , "(Horse's) guiding strap" .)