Reticent to admit sin produced by drink (6)
I believe the answer is:
sherry
'drink' is the definition.
(sherry is a kind of drink)
'reticent to admit sin' is the wordplay.
'reticent' becomes 'shy' (I've seen this before).
'to admit' is an insertion indicator.
'sin' becomes 'err' (to sin is to err morally).
'shy' placed around 'err' is 'SHERRY'.
'produced by' is the link.
(Other definitions for sherry that I've seen before include "Wine from the Jerez region of Spain" , "Alcohol for the trifle" , "Fortified wine originally from Spain" , "Fortified 1 down [WINE]" , "Alcoholic appetiser associated with Jerez" .)