Malty brew (4)
I believe the answer is:
beer
'malty brew' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for beer that I've seen before include "Drink with a head" , "Drink flavoured with hops" , "Hop-flavoured drink" , "It may be 13 across-ed!" , "Stout, for example" .)