When you account for all of the physical and chemical reactions, baking really is a messy sort of science. For example, when you make a cake you must mix and combine the ingredients (a physical reaction, i.e. when molecules are rearranged) and then bake everything in the oven (a chemical reaction, i.e. the molecular or ionic structure is transformed). For this reason, the ingredients that you use can have a big impact on the final product. So, today, instead of discussing a baked good, we’re going to dig a little deeper into baking by looking at the substance (ingredients) and the process.
Substance – The Ingredients
Once all of the ingredients are mixed together and put into the oven, they must somehow combine to form a solitary unit – this is where the binding agents come in. Eggs, heavy cream, and cornstarch are commonly used to make a wet batter come together in the oven to prevent crumbly concoctions.
A good baked good starts with a solid base like all-purpose flour, wheat flour, almond flour, or another gluten-free substitute. Your baked good will require a different set and proportion of ingredients depending on the flour. For example, almond flours require more binding agents (like eggs) to ensure that the baked good does not crumble apart when sliced. Wheat flour is heavier and denser, which means that in comparison to all-purpose flour, you can use wheat flour in lesser quantities in proportion to other ingredients.
With similar names, quantities, and functions, baking powder and baking soda are basically interchangeable, right? Wrong. While they are both leaveners (substances that release gases that therefore make the dough expand), they work in slightly different ways.
Baking soda is a base (i.e. it has a pH of above 7 [as opposed to an acid that has a pH of below 7]) and reacts when it is mixed with acids like yogurt, lemon juice, vinegar, sour cream, etc. to create carbon-dioxide bubbles (the method by which baking soda allows dough to expand in the oven).
Baking powder is a mixture of baking soda (a base) and an acid. The benefit of baking powder is that the leavening process can occur without an acid, so for recipes that don’t call for ingredients like yogurt, then you can still get a nice fluffy baked good just by adding baking powder (as baking soda without an acid would have no effect here).
Some recipes call for both baking powder and baking soda. This may be because some recipes include an acid like yogurt and baking soda, however, the weight of the batter may be too significant for the baking soda alone in relation to the amount of acid. In these instances, one can get some extra lift into the batter by supplementing the baking soda with baking powder.
Baking (chemical reaction)
Heating up the batter in the oven produces an “endothermic” chemical reaction (i.e. a reaction that takes place in heat). In the oven, the leaveners will help the batter rise, the heat will expand and transform binding agents, like eggs, to make the batter firm, and the oils will keep the dough from drying out in the heat.
Creaming (physical reaction)
Creaming is when you vigorously mix butter and sugar together to get a softer, more uniform product. In addition, to physically combining these ingredients, the process also creates air pockets in the batter, which makes it expand.
This was a simple overview of all that happens when one bakes. Anyone can bake, but when you know the purpose of the ingredients and process, you will be better able to judge which ingredient substitutions are appropriate and take more creative risks in the kitchen.
I wish you all the best with your culinary experiments!