When I think of Christmas, I am reminded of the snow, turkey and gift exchanges. One of my favourite gifts to give friends are baked goods I make from scratch. This year, I baked around 200 cookies and instead of the usual chocolate chip, I decided to spice it up a bit and try different recipes. My favourite recipe one was the one for matcha cookies (see picture) that my friends and family absolutely loved.
While scrolling through different cookie recipes, I noticed some of them only had baking powder while others only had baking soda. There were even ones with both! I wondered what made baking powder and baking soda different and how to know which one to use.
Well, the only ingredient in baking soda is sodium bicarbonate. It is a base that when an acid like acetic (vinegar) is added causes a neutralization reaction in which carbon dioxide gas is produced (bubbles). In the context of baking, the gas gets trapped in the batter causing cakes and cookies to rise.
The problem with just using baking soda is that the reaction occurs immediately during mixing and the batter doesn’t rise in the oven. To overcome this, baking powder can be used. Baking powder consists of baking soda as well as two acids: monocalcium phosphate and sodium acid pyrophosphate. What is important about these acids is that they react a bit when the wet ingredients meet the dry but the majority of the carbon dioxide is produced in the presence of heat (e.g. when you place the batter into the oven). As a result, more bubbles are formed while your goodies are baking, creating a fluffier texture.
So when do you use baking soda, baking powder or both? Well, if there is an acidic component in a recipe (e.g. lemon juice) and you can quickly get it into the oven, using only baking soda would be a good choice. If not, baking powder is the way to go. With that said, baking powder is not as fast reacting as baking soda, so when additional fluffiness is needed, both are used.
Always remember to check whether a recipe calls for baking soda or baking powder. You cannot substitute one for the other. I learned a few years back that if you accidently use baking soda instead of baking powder, you end up with waffles that have a distinctive metallic tasting.