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How to make a perfect hard boiled egg?

22 mayo, 2021

Hervé This is a French physicist-chemist, member of the “Institut Nacional de la Recherche Agronomique” and the “Académie Nationale de Cuisine”.

He is considered the father of what has come to be called molecular gastronomy or molecular cuisine. This is neither more nor less than the use of science to understand the physical-chemical processes that food undergoes when cooked.

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The idea is that in this way, if we understand the processes that make food transform, we can control them and exercise a more effective technique in the kitchen.

A practical example: the perfect hard-boiled egg.

Do you know how long a hard-boiled egg must cook for it to be perfect? Do you know how to center the yolk in the white? What should we do so that the shell does not break? At what temperature do we cook it?


Let’s consult Ervé This’s book: Elemental Treatise on Cooking, published in Spain by Editorial Acribia.

According to M. This, a perfect hard-boiled egg must meet a series of conditions: the shell must not be broken or stick to the egg, it must come out easily when we remove it; the white must be white and compact; and the yolk must be perfectly centered, well cooked but juicy, and of course without sulfur odors or greenish reflections.

The first thing to do so that the shell does not break during cooking is to make a small hole with a pin in the base of the egg to release the air content of the small chamber in the base. This air is responsible for breaking the shell as it expands with temperature.

So that the yolk is centered in the white we will help ourselves with the centrifugal force. That’s right, we will only have to stir the water with a certain intensity from time to time during the first 3 or 4 minutes of cooking. That is how long it will take for the white to solidify.

And so that the egg remains with the yolk well cooked but juicy and without the annoying greenish tones, we must control the temperature and the cooking time. The greenish tones of the yolk are nothing more than iron sulfide precipitated by excessive cooking of the white proteins. Therefore, it will be crucial to establish from what temperature this happens.

Well, taking into account that the white solidifies at 62ºC and the yolk at 68ºC, M. This recommends cooking the eggs for a little more than 10 minutes at 69ºC. Of course, this “little more” will depend on the size of the egg and its initial temperature.

For those of us who do not have the possibility of such exhaustive control of the cooking temperature, we will have to settle for the traditional method. Boiling water, this is at 100ºC, and a cooking range of between 8 and 10 minutes depending on the size, the initial temperature of the egg, and our personal tastes.

With this and a few tests to find the right point of creaminess to the yolk, we are sure to be right.

More information | Editorial Acribia En Directo al Paladar | How to cook eggs well, Tricks to determine if an egg is fresh or not En Directo al Paladar | Discipline of molecular cuisine, Molecular Gastronomy, Kientzheim Sauce and Hervé This Egg