Bad smell of yeast in kitchen (5)
I believe the answer is:
stink
'bad smell' is the definition.
(I've seen this before)
'of yeast in kitchen' is the wordplay.
'of' indicates a hidden word.
'STINK' is hidden in the letters of 'yeast in kitchen'.
(Other definitions for stink that I've seen before include "Nasty smell" , "Horrid smell" , "trouble" , "Foul smell" , "Pong" .)