Baking soda and Baking powder both are leavening agents used in cooking and baking. These two kitchen ingredients can be easily confused with each other because of the similar name and similar appearance (White Color), and the similar use doesn’t help either. It is very important to understand the difference because if used interchangeably can cause disaster with whatever you are baking of cooking.
The short answer for this is that baking soda is a base and baking powder is a base mixed with acid and stabilizing agent which is inert in its natural state. And for the long answer please read the details below.
Baking soda has only one chemical compound that is sodium bicarbonate, it is a base and is alkaline which reacts with acid like vinegar or lemon juice when mixed together and releases carbon dioxide in the form of bubbles or foam. When baking, the carbon dioxide is released after the baking soda is mixed with the batter or dough, the carbon dioxide is trapped inside the dough which makes the dough or batter rise. Baking soda reacts immediately to the acid present in the dough or batter so you should bake right after mixing or the product might end up flat or dense. The kneading of the dough should be minimal after mixing baking soda because the kneading process releases the trapped CO2 leaving the product flat. Too much of baking soda used if not balanced with acid will leave metallic after taste in the product, so use it carefully.
All the leavening occurs as soon as the baking soda is mixed with batter or dough. But if your recipe requires longer release of CO2 or the leavening to occur in stages then the Baking Powder comes into play.
Baking powder is a combination of baking soda, one or two acid and a stabilising agent which is usually corn starch. No external acid is added in the batter or dough for the leavening process. The baking powder is already balanced hence there is no need of any external acid to add in the recipe. There are two type of Baking powder i.e. single acting baking powder and double acting baking powder.
Double Acting Baking Powder: This baking powder contain second acid i.e. sodium acid pyrophosphate or sodium aluminium sulfate. Neither of this two acid react with baking soda until they are both wet and hot. The condition for the leavening reaction to happens is that there should be water as well as heat present for the release of CO2. This happens when the dough or the batter is entered in the oven, once the heat is added second stage of CO2 release happens leaving the product risen and fluffier. Because of the double acting baking powder the dough can be kneaded as per the requirement and can be kept to rest (Proofing) because the second release of CO2 will still happen once heat is added to the dough when entered in the oven.
How to Differentiate between Baking Soda and Baking Powder
- Take water in two separate bowl made of glass.
- Add spoonful of baking soda on one and baking powder in another.
- The one with baking powder with have immediate formation of bubble making the water milky because of the acid and base both present in the powder and the water acted as the catalyst for the reaction to happen releasing the CO2 bubbles.
- The one with baking soda will just sit in the bottom because it is just base and for the reaction to occur there should be acid present and water is neither acid nor base its neutral.