Around here we talk a lot about the Maillard reaction. There’s a good reason for that. When you sit down to tuck into a nicely browned steak, a piece of poultry with deep mahogany skin, or bread with a honey-brown exterior, you’re reaping the benefits of the Maillard reaction. This chemical reaction—technically, a complex series of reactions— is responsible for not only changing the color of these foods but also adding a vast amount of flavor.
This reaction occurs almost daily in the kitchen when you cook food that contains protein—which is practically every food. But understanding what’s behind this browning—and how you can control how much or how little of it occurs—can make you a better, more assured cook.
What Causes the Maillard Reaction?
The Maillard reactions start with protein and sugar. When heated above around 250 degrees, an amino acid molecule (aminos are the building blocks of protein) will react with a sugar molecule, forming a new molecule called a glycosylamine. That exists only very temporarily and then undergoes further chemical transformations. It can take a number of different paths, depending on what other molecules are present, and hundreds of different possible compounds can be formed.
What Flavors Does the Maillard Reaction Produce?
The flavors that result from Maillard reactions generally fall into the savory-roasty camp, but there are compelling layers of complexity, with floral and earthy flavors arising due to the wealth of chemical variation in any food. Even though browning chicken and browning beef are both Maillard reactions, they will produce very different-tasting results because the starting protein is different.
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At least one plant-based meat company (Impossible Foods) has harnessed this phenomenon, and deliberately adds ingredients to their soy-protein recipe that influence the progression of the Maillard reactions when it’s cooked and make it take on a distinctly meaty flavor.
And, although we most commonly think of Maillardization when we’re searing or roasting protein-rich main courses, the reach is much broader than that. Maillard reactions are also responsible for the wonderful flavors of baked bread, golden pancakes, roasted coffee, and many other foods that undergo browning through heating.
Even some types of self-tanner work by initiating Maillard reactions in skin proteins, turning them tan.
How Can You Increase Maillard Reactions?
As true fans of Maillard reactions, we rely on a number of techniques to maximize them when cooking.
- Add sugar to a marinade, rub, or glaze. Because the reaction requires both protein and sugar to kick off, adding a bit of sugar to a protein-based food, sometimes in the form of a marinade or a glaze, will speed up browning. Plain white sugar works, but it needs to break down into smaller sugar molecules before it can start, so we like to use honey, whose abundant free glucose and fructose are ready to react right away.
- Add a source of protein, such as soy sauce, to a vegetable. Conversely, when an ingredient has more sugar than protein, we sometimes add amino acids to help it brown, for instance in the form of soy sauce.
- Add baking soda. Raising the pH of food will also speed up the reaction. That’s why we put baking soda on these steaks, and that’s also the secret of the deep, glossy browning that a lye dip (a far stronger base) imparts to pretzels.