Baking is a fun and creative process, and part of being able to experiment with and improve recipes is understanding some of the basic science behind baking. There are so many ingredients and steps in baking, and many questions can arise. What exactly do eggs accomplish in baking? What is gluten, and why is it important? What causes batter to set up in the oven? In this post we will explore some of the basic scientific processes that occur throughout baking, and hopefully answer some of these questions as well!
Many (but not all) recipes for cakes, muffins, brownies, and other dessert bars follow these same basic steps: cream together the softened butter and sugar, beat in the eggs, fold in the dry ingredients, then add any remaining wet ingredients. It turns out that you add the ingredients in this order for a very specific reason.
Creaming the Butter and Sugar
What it means: The term "creaming" in baking simply refers to the act of thoroughly mixing and whipping ingredients together. This can be done by hand with a mixing spoon or whisk, or in a mixer with a paddle or whisk attachment. In order to "cream" the butter (or other fat) and sugar together, it is important that the butter be softened (about room temperature or slightly warmer), but not completely melted. The butter and sugar are properly creamed when the mixture resembles frosting; it should be very light in color and airy in texture.
Why it is important: As you whip the sugar into the fat, the crystalline structure of the sugar cuts little air pockets into the butter/ fat. These air pockets are very important, and you will see why as you keep reading!
Beating in the Eggs
What it means: To "beat" in the eggs just means to mix or whisk them into the butter mixture in a way that adds air into the batter. If mixing by hand, this is typically done with a mixing spoon or whisk, mixing the eggs into the butter in a fast circular motion. If using a stand mixer, the eggs can just be mixed in at a slightly higher speed in order to whip some air into the forming batter.
Why it is important: As the eggs are beat into the butter mixture, the air bubbles that were made previously (by creaming the butter and sugar together) are coated in protein from the eggs. Having the air pockets coated in both fat and protein protects them throughout the baking process. In addition to adding this vital protein, both the egg yolks and egg whites play other important rolls. The egg whites add much needed moisture to the batter, and the egg yolks act as an emulsifier to blend all of the ingredients together.
Folding in the Dry Ingredients
What it means: "Folding" is a baking term for gently mixing dry ingredients into the batter. Much as we love the dramatic scene in Shitt’s Creek about folding ingredients together, this is actually a very simple technique. This is done using a spatula to scrape along the bottom of the mixing bowl in order to bring the contents from the bottom of the bowl to the top. Repeating this motion over and over while rotating the bowl combines the dry ingredients into the batter, while not disrupting the air pockets that you have worked so hard to make. It is important to be gentle here! Dry ingredients typically include flour, salt, baking powder or baking soda, and spices.
Why it is important: There are a couple of different reactions that occur when the dry ingredients are added to the batter at this stage. First, when combined with liquid, the proteins in flour develop the gluten (present in regular flour) and create an elastic network around the air pockets in the batter. Gluten is best described as what makes batter or dough stick together. If you have ever kneaded dough and seen how you can stretch the dough so that it looks kind of like elastic, this is all due to the gluten molecules holding everything together. In the batter, this network of gluten encloses and protects the air pockets, which is important for the actual baking process.
The second reaction occurs when the liquid activates the leavening agent (baking powder or baking soda) and creates a release of carbon dioxide. The carbon dioxide creates additional air pockets in the batter that grow throughout the baking process and cause the batter to rise.
Mixing in the Wet Ingredients
What it means: The final step in creating the batter is mixing in the remaining wet ingredients, such as milk, buttermilk, or water. This is typically done with a spoon if mixing by hand, or with a paddle or whisk attachment if using a mixer. The air pockets are better protected at this stage, but it is still important not to over mix the batter or the gluten will over develop and make the final baked product tough.
Why it is important: This added liquid has a couple of benefits. The liquid strengthens the gluten bonds from the flour, creating a more stable structure. As the batter is baked, steam is also released from the liquids. This steam gets trapped inside the air pockets and helps them grow, aiding in the rise of the final bake.
When the batter is placed in the oven, the heat activates the leavening agent even more, so that more carbon dioxide is released into the batter. Steam from the evaporating liquids causes the air pockets to grow and the batter to rise. The network of gluten, protein, and starch trap the air pockets as they grow, and this starts to form the final structure for the baked product. In the final stages of baking, the egg proteins coagulate and the starch from the flour absorbs the remaining liquid. This causes the batter to finally set and form the final baked product.
The last step in the baking process is browning. The sugars in the batter break down into amino acids, and this creates a browned crust around the top and outside of the bake.
After all of these processes are complete, you are left with an amazing baked good to enjoy with your loved ones! We hope that knowing a little bit about the baking process will encourage you to try out some recipes and be creative. Baking should be a fun and exciting process, and the more you know about it, the more creative and adventurous you can be!