To understand the chemistry behind baking, we can start with each component that we usually use in the baking process and see how chemistry plays a big role in baking:
- Flour: basis of much of baking and also the source of protein (gluten). This protein provides structure to baked goods and gives the bread its fine texture.
- Yeast: a microorganism that consumes starch and sugar and in the process, alcohol, carbon dioxide and sugar are released. The elastic dough traps this carbon dioxide and gets it light, airy texture.
- Fat: traps the carbon dioxide molecules and lends a softer texture.
- Sugar: is the main food source of yeast and its metabolism causes release of CO2. Sugar also keeps the baked items moist by preventing the formation of gluten.
- Baking powder: it reacts with acids to form carbon dioxide.It is used instead of baking soda, because the soda releases a strong base, which is neutralized here.
- Egg: acts like a leavening agent, egg white helps in retaining CO2 bubbles and egg acts as a binder. Egg yolk provides richness and moisture.
- Salt: balances flavor and makes the dough more elastic by lining up the gluten fibers (due to interaction between salt ions and amino acids in the flour).
Hope this helps.