If your cornmeal is instant, look on the back label and see if there is any sodium, or is it rising flour etc. If it is, then do not add baking soda because it does act like a rising agent and no need to add salt at all if it has sodium in it already!!! Sometimes If I have on hand, I add mineral sparkling water instead of baking soda. If you don't like it too sweet add less sugar. Sour cream is used to keep cornbread moist.