Imagine waking up to the smell of hot buttered toast or the joy of a beautifully charred steak with oodles of caramelised onions. These rich, roasted flavours that we love so much are all the doing of the Maillard reaction, a complex chemical process that is everywhere you look in the world of food. Even your strong morning coffee has the Maillard reaction to thank for its robust flavour.
Chances are you’ve probably already harnessed the power of this process when you’re cooking but even though its effects are common, the reaction itself is infinitely complex. In fact, it’s not really one reaction at all but a series of small simultaneous chemical processes that occur when proteins and sugars in your food are transformed by heat.
As humans, we’ve been biologically conditioned to find the taste and smell of cooked food more appealing as our instincts kick in telling us that it will provide us with nutrition while also being safer to eat than raw food. The Maillard reaction helps us get to that stage because when the right amount of heat, moisture and time come together in a pan, the proteins and sugars in a dish fuse together and form an edible pigment molecule called melanoidins which are responsible for giving cooked food a darker colour.
The most important factor is heat, but not just any amount of heat will do. For example, if you boil a steak it won’t turn brown but grey and that’s because boiling water only reaches a maximum of 100°C, which just isn’t enough to get the Maillard reaction going. It can work at lower temperatures if there’s a lot of liquid involved – such as with a 10 or 12-hour braised chicken – but most of us don’t have time for that on a daily basis. That’s why frying, roasting and grilling are the preferred ways to get to the 149°C that the Maillard reaction needs to take effect.
So when heat, moisture and time are accounted for, the next requirement is for the presence of ample proteins and sugars. Proteins are made from chains of amino acids but not all of them are susceptible to the Maillard effects. The sugars too, need to be of a certain type to be able to bond with the proteins. Starches and table sugars are too big instead, reducing sugars are needed to attract amino acids at the correct moisture and temperature level. With such limited numbers of viable proteins and sugars, the reaction begins slow but then the elements bond and mix with time creating billions of new molecules every second to slowly cover the surface of your food with a new colour, aroma and flavour.
But the Maillard reaction isn’t the only one that can occur between proteins, sugars and water, caramelisation is another process that occurs but in different ratios. And while the two may look very similar, they produce a different flavour profile with caramelisation being nutty, sweet and sometimes even slightly bitter. They’re not mutually exclusive though and both can take place together to produce a truly beautiful kaleidoscope of flavours.
At the end of the day, the Maillard reaction teaches us that cooking isn’t just an art form, it’s a science. There are set reactions to every action you make and if you brush up on your kitchen chemistry, there’s nothing stopping you from cooking like a pro in your own home.
