Drink helps make job rewarding (4)
I believe the answer is:
brew
'drink' is the definition.
(brew is a kind of drink)
'helps make job rewarding' is the wordplay.
'helps' says the answer is hidden in the clue (I've seen 'helping of' mean this (I've seen this in other clues)).
'BREW' is hidden in the letters of 'make job rewarding'.
(Other definitions for brew that I've seen before include "Ferment rather than distil" , "Infusion" , "Make beer by boiling and fermentation" , "Infuse" , "Ferment, concoct" .)