If you have done any baking at all, chances are you already have the first line of the recipe memorized: preheat oven to 350 degrees. Yes, it’s a fairly nice round number. Yes, it’s also pretty easy to turn the temperature knob to that setting (not too much twisting). And yes, if you have an oven with a digital setting there aren’t too many keypad buttons to push. But that’s not the reason 350 degrees seems to be cooking’s magic number. It’s the chemistry.
There’s actual science why everything from banana bread to crescent rolls to a mac-and-cheese casserole calls for a baking temperature of 350 degrees. It’s called the Maillard reaction and it’s why food tastes so good.
Essentially, it’s the process of browning and it occurs every time you heat a mixture of proteins, amino acids and sugars in food molecules. Think about roasting marshmallows, baking bread, searing a steak, roasting a turkey, or even roasting coffee. That’s the Maillard reaction in action.
“The real specifics of the Maillard reaction occur when an amino acid (which forms the backbone of proteins) reacts with a reducing sugar (such as glucose and fructose) to produce a “browning” type reaction,” said Nicholas Gillitt, Ph.D., chief science officer at the David H. Murdock Research Institute. “The products of this reaction have all sorts of flavors and aromas depending on the individual compounds that end up reacting. And because eating food is a very sensory experience, these products usually enhance the palatability, taste and/or smell of the food enticing us to eat and enjoy.”
To be clear, the Maillard reaction is not just one reaction. It’s many small, simultaneous chemical reactions that occur when proteins and sugars in your food are transformed by heat. And because there are so many reactions happening at the same time, there are many complex flavors produced and many shades of that appealing golden-brown color.
“Cooking temperature, time, pH, and water content are the key factors affecting the Maillard reaction,” explains Shengmin Sang, Ph.D. Professor in the Laboratory for Functional Foods and Human Health, at North Carolina A&T State University at the North Carolina Research Campus. “Manipulation of these factors in home cooking and in the food industry has been widely used to control the final color and taste of foods and food products.”
Louis Camille Maillard was a French chemist, who understood the science behind browned food. He discovered that amino acids and sugars in food molecules change around 350 degrees, transforming the color and creating new flavor profiles. The raw ingredients not only changed color but also produced carbon dioxide. The year was 1912. Maillard was searching for medical breakthroughs. But even though Maillard discovered the reaction, he never quite figured out the science behind browned food.
That didn’t happen until 1953, when John Hodge, a chemist with the United States Department of Agriculture, sorted out the exact chemical happenings in a paper published in the Journal of Agriculture and Food Chemistry. Of course, all of this doesn’t mean that everything should be cooked at 350 degrees. Some foods require a higher temperature. But if you accidentally throw away the directions, 350 degrees is a good rule. Or as Maillard would say, a golden rule.
Frank Graff is a producer/reporter with UNC-TV, focusing on Sci NC, a broadcast and online science series.