Saturday Science Sessions – The Science of Baking
The science of baking is just one example of how we can ask questions and seek out answers about even the most simple experiences in life. Baking is all in the chemistry; and of course the intricate functions of a few simple ingredients.
Ingredients for most baking include flour, spices, sugar, eggs, and a leavener such as baking soda or baking powder. Each of these ingredients play a critical role. For example, some ingredients can strengthen a batter (such as proteins and starches like flour), weaken/tenderize (fats and sugars), or even moisten (such as a liquid). The entire process of baking using heat causes the important chemical and physical reactions that make baking possible!
Flour is probably the most common ingredient we think of when it comes to baking and it provides the structure or foundation. This is a result of the protein in flour (glutenin and gliadin). The bonding process in the proteins begins when a liquid such as water is added for hydration. The result of the moistening process forms gluten.
Then there are the leaveners such as baking powder and baking powder. Have you ever noticed the porous texture of a cake or the air bubbles in the batter? This is the result of these ingredients. Typically all of the ‘dry’ ingredients are mixed together separately from the liquid ingredients, which include eggs (the binder), butter or oil (the tenderizers), and milk or water (the moisturizers)
Once all of the ingredients are mixed together, they are subjected to intense heat in the oven. This is where the chemical reactions take place. For example, the starches and proteins in the flour, along with sugar, creates a webbing structure that traps water and provides moisture inside the baked good. The baking powder or baking soda (a base), reacts with acids (such as lemon juice, molasses, and vinegar) to release carbon dioxide, which causes the baking to expand. A similar process occurs with yeast.
Whatever you are baking, the science is in the ingredients. Light and delicate cookies often involve a fewer number of ingredients, not adding more. A delicate texture can be achieved by removing butter. And brown sugar helps absorb moisture after baking, which maintains softness. The gingerbread cookies I made require a significant amount of brown sugar and I can verify that they are deliciously tender! Conversely, granulated sugar provides a crisp and crunchy texture to cookies, for example.
Baking is both an art and a science; whether cookies turn out crisp and crunchy versus soft, sandy, and tender is a matter of ingredients and methodology. Depending on what you add, how you mix, and the baking process, the science behind treats is both fun and surprising!