I love that it feels like more people know more about food than ever before—and not just because it’s good for business. Understanding cooking methods, and why certain things happen the way they do, is one key to kitchen success. It also gives you the confidence to improvise and experiment.
Sources such as “Modernist Cuisine,” Harold McGee (“On Food and Cooking”) and J. Kenji López–Alt of Serious Eats and “The Food Lab” fame, have helped create a cottage industry in food science. And that’s great. But the more people who read them and try to convey the principles, the more likely it is that certain concepts can get distorted and the errors amplified as they spread, like a game of culinary telephone.
Take the Maillard reaction. If you’ve heard anyone talk about cooking meat, you’ve probably come across the term—and odds are you’ve come across some confusion about what it means. Let’s break it down, and learn why it matters.
What it is
Part of the confusion about Maillard—named after a French chemist who first described the phenomenon—is that it’s often called the browning reaction, but it’s only one type of browning, says Joseph Provost, a chemistry and biochemistry professor at the University of San Diego who co-wrote “The Science of Cooking: Understanding the Biology and Chemistry Behind Food and Cooking.” In Maillard, sugars (more on that below) interact with the amino acids of proteins, creating a cascade of new flavors and aroma compounds, with several hundred possibilities.
“The important thing about the Maillard reaction isn’t the color, it’s the flavors and aromas,” according to “Modernist Cuisine,” by Nathan Myhrvold, Chris Young and Maxime Bilet. “Indeed, it should be called ‘the flavor reaction,’ not the ‘browning reaction.’ ”
The Maillard reaction has about 20 to 30 steps that happen very quickly, Provost says. “We know most of them, but we don’t know all of them.”
While Maillard is responsible for all sorts of enticing flavors and aromas, it’s not without controversy. As Chemical and Engineering News, a publication of the American Chemical Society, explains, the reaction can cause the creation of acrylamide, a potential carcinogen, in highly processed foods cooked at higher temperatures. You can read more from the Food and Drug Administration, which notes that “acrylamide is found mainly in foods made from plants, such as potato products, grain products, or coffee. Acrylamide does not form, or forms at lower levels, in dairy, meat, and fish products. Generally, acrylamide is more likely to accumulate when cooking is done for longer periods or at higher temperatures.”
As to those sugars in meat? Let food scientist and author Robert Wolke, explain, as he did in a Food 101 column published in The Washington Post in 2006: “When we sear a steak, for example, certain parts of the protein molecules (the so-called amino parts) interact with so-called carbonyl groups, which are parts of sugar molecules. ... A carbonyl group is indeed a certain grouping of atoms found in sugar molecules. But it also is found in many other kinds of molecules, including the meat’s very own fats and proteins. The Maillard browning process can use the carbonyl groups that are inherent in the meat; it does not require sugars.”
What it isn’t
Caramelization is another type of browning, so it’s easy to conflate it with Maillard, especially because you can get both types of reactions at the same time, Provost says.
Caramelization, however, specifically refers to when sugars, and only sugars, are exposed to high temperatures. “The sugars break down and turn successively yellow, tan, brown and darker brown, while developing that complex, sweetly pungent flavor we call caramel,” Wolke wrote in The Post in 2002. It’s also worth keeping in mind another related point from Wolke—that not all browning is caramelization, either.
When it happens
Maillard happens all the time in all kinds of food: Meat, of course, which is the context most of us know. But you’ll also find its influence in everything from coffee and toast to chocolate and beer. What gives the reaction so much variation is the differences in the amounts and types of sugars and proteins in the different foods.
Specifically, Maillard kicks in around 300 degrees.
Make it work for you
You can’t always control Maillard, but you can maximize its potential in certain situations. Again, those often involve meat. Provost recommends getting your meat as dry as possible before cooking, which means the energy in the skillet can go toward browning the food rather than evaporating surface moisture. That can be done by patting the meat dry or, as a longer-term strategy, salting meat a day in advance and letting it dry in the refrigerator. If you’re going to be braising or using a slow cooker, consider browning your meat first, because meat submerged in liquid will not reach a temperature above the boiling point of 212 degrees, making Maillard hard to achieve. But if you sear initially, you’ll still get the benefits of the flavors and aromas generated, even if the meat is transferred to a moist environment.
Baking soda can also give an assist in speeding along Maillard by creating a more alkaline (higher pH, or basic) setting. That’s why you might see baking soda used in a water bath for pretzels or in caramelized onions. Some recipes employ baking soda to help meat brown faster as well.
For breads, Provost extols the virtues of an egg wash to promote Maillard so that the proteins in the egg can interact with the sugars in the dough for appealing toasty flavor. Cook’s Illustrated notes that the type of wash can also affect the degree of browning. Water will give decent browning with little shine, with both features increasing as you move on to milk, whole eggs, egg whites and lastly to egg yolks, which impart very good browning and an intense shine.
Higher heat can promote the Maillard reaction, too, up to a point. Above 355 degrees, “Modernist Cuisine” says, you get a different type of browning: pyrolysis, or burning.