Scientists crack the code for the perfect boiled egg

Difficulty: Challenger (Level 2)

The perfect boiled egg has a velvety yolk and a soft, solid white. However, achieving this can be challenging.

This is because the yolk cooks at a lower temperature than the white. Hard boiling an egg can result in a chalky yolk. But cooking low and slow can produce jellylike, undercooked whites.

Researchers cooked hundreds of eggs and used maths to tackle this problem.

Their final recipe involves transferring eggs in a steamer basket every two minutes between two bowls of water. One bowl has boiling water, and the other has lukewarm water at 30 degrees Celsius. The whole process takes 32 minutes (see graphic).

“You could definitely do this at home with half a dozen eggs or so,” said Gregory Weiss, a chemist at the University of California, Irvine, who was not involved with the research.

In the method suggested by the researchers, the egg whites were heated and cooled until fully set. At the same time, the yolk held firm at a constant temperature and cooked until it was creamy.

“You can almost spread it, like on bread,” said study author Emilia Di Lorenzo from the University of Naples Federico II.

To confirm they had cooked up something new, the researchers tested the chemical make-up of the prepared eggs. The eggs were then served to a panel of eight tasters along with traditional boiled eggs.

The research was published in February.