Function of baking soda in baking?

Answer 1

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 dioxide that, when heated, expand causing baked goods to rise. The reaction begins immediately upon mixing the ingredients, so you need to bake recipes which use baking soda immediately.

Answer 2

Baking soda is a leavening agent used in baking to help baked goods rise. When mixed with an acidic ingredient (such as yogurt or buttermilk), baking soda produces carbon dioxide gas which creates small air bubbles in the batter, making baked goods light and fluffy.