Baking soda, for short (6)
I believe the answer is:
bicarb
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">baking soda for short</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for bicarb that I've seen before include "Digestive remedy (abbr)" , "Chemical" , "It helps digestion" , "What helps raise" , "source of fizz?" .)