Chemically speaking baking soda should raise the pH. Acids are low pH and baking soda high pH so you'll just have to figure out how much. If you are adding baking soda reduce the salt because the chemical reaction between the Sodium in baking soda and the acid of the tomatoes may produce a salty taste. (I have 24 hours of college chemistry plus spent most of my working career doing reseach in medical schools. I have also taught HS chemistry. So I am sure of the basic chemistry---please do not get offended but consider this me giving my justification for my advice.)
Posts
Re: baking soda is high pH ...so it should netutralize the acid
