Baking soda, for short (6)
I believe the answer is:
bicarb
'baking soda for short' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for bicarb that I've seen before include "Digestive remedy (abbr)" , "Chemical" , "It helps digestion" , "What helps raise" , "source of fizz?" .)