One can never forget the unctuous aromas that fill the room over Thanksgiving as the beautifully roasted turkey is placed at the center of the table. The crispy skin, juicy and tender meat, and its gorgeous brown hue are all memories one can cherish on a cold rainy day. There are various other such moments where roasted dishes are the showstoppers of a meal and believe it or not, there is an actual science that goes behind this age-old cooking method.
The scientific concept of the Maillard Reaction, that we are about to review in this short read is based on an encounter by Louis-Camille Maillard. He discovered that upon gently heating sugars and amino acids in water, a yellow-brown color developed. Simply put, Maillard reaction is the basis of roasting and is an extremely complex process that is the reaction between reducing sugars and proteins by the impact of heat.
So, that delicious crackling skin on Thanksgiving turkey and Peking duck, the decadent aroma and color of roasted coffee beans, the silky-smooth consistency of Peruvian chocolate are all the end products of Mr. Maillard’s discovery. Roasting occurs when heat transfer is used to eliminate moisture from a product, giving way for sugars and proteins to react.
Let me try and explain this reaction with the help of an analogy. Think of the molecular structures of sugars and amino acids as two opposing parties in a battle. When heat is applied (above 120 C), the amino acids start attacking the glucose molecule (sugar is made up of glucose and fructose) and form a bond. Once this bond is formed, it leads to the molecule falling apart and a chain of several other reactions; other amino acids reacting with glucose, amino acids bonding with the carbon atoms and so forth. Imagine all of these different chemical reactions with their end products producing flavors and aromas that depict savory and earthy tones: those of onions, potatoes, and robust meatiness. The process of the Maillard reaction is basically an intense and bloody battle, just one that tastes good.
We have now discovered that Maillard reactions on meats, vegetables or anything else, tastes really good. So how do we get more of it? And how do we get it easily? The answers lie in sodium bicarbonate or baking soda. Adding baking soda (or any other alkaline substance) to an amino acid will make it a better attacker of the carbon in glucose. This will result in more and faster Maillard reactions throughout the ingredient. This is an important factor when it comes to baking as the addition of baking soda ensures an even and increased browning throughout the cookie, cake, biscuit or anything else from the Great British Baking show that you are about to attempt.
Now that we have scratched the surface of the science behind roasting, there are a few key pointers that I, a chef and not a food scientist, am going to give you to achieve the perfect roast. Firstly, and probably the most important one, is the absence of moisture from the piece of meat or vegetable that you are trying to roast. Curing in salt and air drying are some methods that can be used to get rid of excess moisture from proteins. Secondly, the temperature of your oven is crucial. If proteins are not roasted at high temperatures (350F-400F), our amino acids won’t have conducive conditions to attack the glucose, resulting in a pale and not-so-delicious exterior. Lastly, be informed about the cut of meat that you are using and adjust the time and temperature accordingly. If you roast a filet mignon for 30 minutes at 350F, you might as well have thrown your cash out the window. Stick to slightly tougher cuts such as prime ribs, legs of lamb, pork butts etc.
Understanding the science behind basic cooking principles gives you an innate appreciation for food and how you are able to manipulate what you eat. If you apply the aforementioned principles and learnings to your roasting endeavors, you are guaranteed to wow your guests with the roast of their dreams.