Baking soda is pure sodium bicarbonate. When baking soda is combined with moisture and an acidic ingredient (such as yogurt or buttermilk), the resulting chemical reaction produces bubbles of carbon...
Also called baking soda. When combined with an acid (yogurt, sour cream), it begins to produce gas bubbles.
It makes the dough go through a proses of fermentation which makes it expand so bread or cakes rises and get softer and fluffier.
It causes your recepie to rise. ------- Thermal decomposition of baking soda and releasing of carbon dioxide and water vapours.
to make recepies rise it helps the cake to rise during cooking making it light and spongy