The chef Fernand Point, father of modern French cuisine, was famous for testing his potential assistants by asking them to cook a fried egg. That’s right, a simple fried egg was enough to make or break the dreams of even the most promising young chefs. Why? Because the proper cooking of an egg has to adhere to two delicate aspects: its molecules and how they react to the external surroundings, thanks to that physical parameter called temperature.
Composition and temperature are two essential factors in cooking all dishes – and so the experience with a mere egg can be applied to many other procedures, which we will talk about in the attachments. But for now, let’s concentrate on the noble oeuf, unveil its secrets and the tips and tricks for cooking it the way Point would wish.
Seeing as we’re citing a French chef, let’s begin with Point’s preferred way of cooking an egg. It’s also the most complex, but it allows us to learn all about the secrets contained in a simple egg. First step: break one delicately over a plate. You’ll see a clear part (the white) and the yellow part (the yolk). These are the two edible parts, and are so different because the composition of each part is so diverse.
The white is composed of 10% protein and 90% water, while the yolk contains the fat. And we already know that fat and water don’t mix very well. Think of cold beef broth, for instance, when you can see the separation of the two components. This is the same reason why yolks and whites are so separate. What interests chefs in the whites of eggs, is the protein. This kind of protein is made up from organic compounds that are among the most important when it comes to cooking, both from the nutritional point of view as well as aesthetics (thickeners and gelatin both contain them). And these proteins behave in specific ways according to temperature. Think of protein like a necklace, composed of small pieces called amino acids and then folded into shapes which could be either more or less complex. When we heat them, they unfold – or in scientific jargon, they become “denatured”.
In the case of the egg white, the denaturation makes the protein take a new shape and structure, trapping the water that surrounds it and transforming it into a kind of white, solid gel: it’s the cooked egg white that we’re already so familiar with. Denaturation is a simple process, but one that requires a constant control of the temperature: egg proteins begin to denaturize at 62°C. If you heat it slowly, they create a more orderly structure, with a compact, juicy white. If the temperature is too high, instead, you risk burning, which will make it hard and unpleasant. This is the one, great secret for a perfect fried egg: put a knob of butter into a pan and let it melt over low heat. Seeing as its hard to use a thermometer in a frying pan, you need to train your eye: the right moment to add the egg is just before the butter begins to bubble.
At this point, let the egg white and yolk slide gently into the pan. The rule is that the yolk should be at the centre of the white, so use a wooden spoon or spatula to adjust its position. The proper temperature should ensure that the egg white begins to coagulate immediately: cooking time is between 4 and 6 minutes, after which the perfect consistency is reached – not too cooked because to do that you’d need to reach 68°C to completely solidify. While we wait, melt another knob of butter. When finished cooking, add salt, pepper and the melted better on top. Adjust the salt at the end, otherwise you’ll slow the cooking time and could ruin the perfect coagulation of the egg white.
The same considerations are valid here as well. And again, the secret lies in the heat – even though the use of water allows us to use a thermometer if necessary, to guarantee that the temperature is constant between 64° and 65°C: just hot enough to cook the white but not the yolk, which should be warm and creamy. This is why it’s not advisable to place the egg in boiling water, which is 100°C: if the protein denaturizes too fast then the white will get too stringy and the yolk may cook too much. Cooking time? At 64°-65°C you’ll need at least fifty minutes, and having put the egg in water which is already the proper temperature will provide a thermal shock that renders it even tastier. The result? Perfection.
The fundamental difference with this result is the yolk, which must be solid for a hard-boiled egg. The yolk is about 27% fat, but also contains a good dose of protein (16%), vitamins and minerals. There’s also water, but it’s trapped within the fat particles, so it’s hard to distinguish. And it’s thanks to the presence of protein that the egg solidifies when heated. This specific combination of elements allows the yolk to harden between 65° and 68°C, at a higher temperature than protein. For a hard-boiled egg, then, we should use water at 70°C, and a half an hour is the needed time. Of course, this will vary according to the size of the egg – the large or extra-large ones will need a few more minutes. See? Just a basic grasp of science can guarantee great satisfaction at the stovetops. Fernand Point would hire us on the spot.