Why Does Food Turn Brown When Baked?

We have all seen how food becomes more golden brown as it is cooked or baked, but do you know why this happens? This browning is due something called the Maillard reaction. This post will go into the details of the science behind this tasty phenomenon.

The Basics of the Maillard Reaction

In short, the Maillard reaction is a chemical reaction that happens between amino acids and sugars that occurs at high heat. This reaction results in the characteristic browning of a baked good and also enhances the flavor and aroma.

Temperature Matters

The Maillard reaction takes place when food is heated to a temperature between 280-330 degrees Fahrenheit. Lower temperatures are not conducive to this reaction. Once food reaches a temperature above about 350°F, the food will begin to burn and char. So if you are trying to enhance the aroma and flavor of your food using the Maillard reaction, make sure you are keeping the food in that sweet spot.

How to Promote More Browning

There are a couple of common methods used to promote browning from the Maillard reaction. One way is to brush a baked good with an egg wash before baking. This is commonly done for flaky pastries such as croissants. The egg provides more protein to supply the amino acids that react with sugars to produce the browning. Another way is by using a lye or baking soda wash (like with pretzels). The solution used in this method is alkaline, which changes the pH of the dough and accelerates the Maillard reaction.

Different from Caramelization

It should be noted that the Maillard reaction is not the same as caramelization. Caramelization is a reaction that involves only the sugars in food whereas the Maillard reaction includes both sugars and amino acids. Both reactions can result in food turning a brown color, but the chemistry and resulting flavors are different. Caramelization also takes place at a higher temperature than the Maillard reaction.