Extract of malt is an essential for some infusions (7)
I believe the answer is:
tisanes
'some infusions' is the definition.
(I've seen this before)
'extract of malt is an essential' is the wordplay.
'extract of' indicates the answer is hidden within the clue (I've seen this in other clues).
'TISANES' is hidden within 'malt is an essential'.
'for' is the link.
(Other definitions for tisanes that I've seen before include "health drinks?" , "infusions" , "Herb teas" , "Brews" , "More than one hot drink" .)