Stop alcohol being added to German sweetmeat (4,6)
I believe the answer is:
stem ginger
'sweetmeat' is the definition.
'stop alcohol being added to german' is the wordplay.
'stop' becomes 'stem' (stemming is a kind of stopping).
'alcohol' becomes 'gin' (gin is a kind of alcohol).
'being added to' is a charade indicator (letters next to each other).
'german' becomes 'ger' (abbreviation).
'stem'+'gin'+'ger'='STEM GINGER'
(Other definitions for stem ginger that I've seen before include "Merging set (anag.)" , "Plant root of a pungent spice" , "It's tasty" , "spicy ingredient" , "Crystallised root" .)