Hard-boiled, soft-boiled or poached? Scientists have studied how to cook the perfect egg and have come up with a new recipe that they say optimizes its taste and nutritional quality.
Cooking an egg is a delicate art because the yolk and the white do not cook at the same temperature. The yolk begins to solidify at 65 degrees Celsius and the white at 85 degrees.
To avoid ending up with a soft-boiled egg, chefs have to choose a "compromise temperature", said the authors of a study published on Thursday in the journal Communications Engineering.
In the case of a hard-boiled egg -- cooked for 12 minutes at 100 degrees Celsius - all parts of the egg have a final temperature of 100 degrees, well above the ideal cooking temperature, particularly for the yolk.
In the case of egg sous vide, which is cooked between 60 and 70 degrees, the final egg is at a temperature of 65 degrees. But while this is the ideal temperature for the yolk, it is much too low for the proteins in the egg white to stick together.
As for the soft-boiled egg, cooked for six minutes at 100 degrees, the authors say the egg yolk is undercooked.
The Italian polymer specialists approached the problem by simulating the process with the help of computational fluid dynamics software, which was used to simulate and analyse the flow of fluids and their interactions with solid surfaces.