The Chemistry of Cooking

Have You Ever Wondered..

Why does a clear egg white turn solid when it hits a hot pan?

How does a flavorless piece of dough turn into a golden, fragrant loaf of bread?

Why does a cut apple turn brown if you leave it on the counter?

Cooking is the ultimate science experiment where heat and ingredients transform into delicious discoveries.

Denaturation happens when heat changes the shape of proteins, which are like tightly wound balls of yarn—when heated, they unravel and stick together. This is why a liquid egg turns solid when it cooks.

The Maillard Reaction: When heat makes sugars and proteins react, food turns brown and flavorful, like toast, steak, and cookies.
Phase Changes: Cooking uses heat to change matter, such as melting solid butter or turning water into steam.

Kitchen chemistry uses acids and bases to change the texture and color of our food.

Chemical Lift: Baking soda is a base. When you mix it with an acid (like lemon juice or buttermilk), it fizzes up and releases Carbon Dioxide. These tiny gas bubbles get trapped in the dough, making your pancakes fluffy.
Stopping the Brown: When you cut an apple, it reacts with oxygen and turns brown. Adding an acid (such as lemon juice) “turns off” the enzymes that cause this reaction.
The Power of Salt: Salt isn’t just for taste; it’s a chemical tool. It acts like a “molecular glue” that strengthens bread dough, allowing it to hold its shape as it rises.

Here are some interesting facts about the chemistry of cooking:

Fish can be “cooked” without heat in dishes like ceviche, where acid from lime juice denatures proteins and makes the fish firm, just like heat would.
Custards and sauces can turn lumpy if heated too quickly because starch molecules tangle instantly instead of thickening smoothly.
Spicy foods feel hot because capsaicin tricks pain receptors into sensing heat. Since it is oil-based, water spreads it, while milk helps wash it away.
Honey never spoils because its low water content and high acidity prevent bacteria from surviving, which is why edible honey has been found in ancient tombs.

Let’s quickly recap what we learned about the chemistry of cooking:

What is the term for proteins unraveling due to heat? Denaturation
Which reaction creates the brown, flavorful crust on bread? Maillard Reaction
What type of reaction causes a sliced apple to turn brown? Oxidation
What ingredient is used to strengthen gluten in dough? Salt