What is the chemical reaction for when you are baking cookies?

Answer 1

This is really a complicated question! There are many, many reactions that occur when you bake cookies, some are simple and some are complicated. This answer may be rather long, but bear with me!

• When you first mix the dough, some of the most complicated reactions occur. When water is mixed with flour, the proteins gliadin and glutenin in the flour combine to make gluten. This is a very complicated chemical reaction, and is what makes dough or batter stick together! This reaction is also essential for making dough rise, because without the gluten, the air (actually CO2) created inside the dough will just escape, and your dough will be flat!

• After adding flour and water, you at least have to add sugar and baking soda to make a cookie dough. When you add sugar, it reacts with the water and breaks up. You can picture this as if a sugar molecule is a figure eight, and then its splits into two rings. These two rings are called monosaccharides, while sugar is a disaccharide. This reaction is well understood, and is taught in High School chemistry.

• When the dough looks good, you put it in the oven. When the dough is in the oven, more chemical reactions happen. The most important is between water and baking soda. This reaction produces CO2, which is a gas, the same gas that gives fizzy drinks their fizziness. The CO2 in the cookies help them rise and become light in texture, instead of lumps of hard dough.

• Several other reactions occur in the oven, and another important one is the evaporation of water. You may not think this is a chemical reaction, but it is! This reaction transforms wet cookie dough into crunchy, delicious cookies, so you understand why it is important.

If you really want to dig deep into the workings of cookie dough, there are many more reactions occurring, such as the Maillard reaction which is responsible for turning cookies brown when baking, and the protease enzyme reactions that break down gluten. This last one is the reason most people add a pinch of salt to their cookie dough, so that the gluten made by flour and water isn't destroyed. Wow, who would have thought that cookies were so complicated? Fortunately, they are much easier to make!