Scientists say they have cracked the way to cook the “perfect” boiled egg… but it takes 32 minutes. The Italian research team say the new method – which they call “periodic cooking” – is “optimal” for boiling both the yolk and white of a chicken egg.The pioneering approach provides an evenly-cooked egg with a higher nutritional content than shell-on eggs cooked by conventional boiling or sous vide methods, according to the study published in the journal Communications Engineering.
But it won’t be much good for anyone wanting a quick-fix breakfast as it takes over half an hour to prepare the ideal boiled egg using the periodic cooking method. Study leader Dr Pellegrino Musto said: “The yolk and white in chicken eggs cook at two different temperatures: the albumen cooks at 85 degrees Celsius, while the yolk cooks at 65 degrees Celsius.Conventional methods for cooking eggs by hard-boiling at 100 degrees Celsius result in the yolk being fully set, while cooking them at temperatures between 60 and 70 degrees Celsius in a water bath for one hour – a method known as sous vide – leaves the white undercooked.”
Dr Musto, of the Italian National Research Council, and his colleagues developed the method for consistently cooking eggs by first simulating the process in computational fluid dynamics software. He said: “The simulations suggested a method that consists of alternating an egg between a pan of boiling water kept at 100 degrees Celsius and a bowl kept at 30 degrees Celsius, transferring the egg from one to the other every two minutes for a total duration of 32 minutes.”
The research team then trialled the process in real life to produce food samples to analyse. Hard-boiled, soft-boiled, and sous vide eggs were also included in the analysis — the final cooked eggs were tested for their texture and sensory qualities, with their chemical properties evaluated using Nuclear Magnetic Resonance and High-Resolution Mass Spectrometry.
Dr Musto said: “Periodically-cooked eggs had a soft yolk similar to that of a sous vide egg, while the consistency of the white was somewhere between that of sous vide and soft-boiled. Temperatures in the periodically-cooked egg white ranged between 35 and 100 degrees Celsius during cooking, while the yolk remained at a consistent temperature of 67 degrees Celsius.”
He added: “Chemical analysis suggested that the periodically-cooked egg yolks also contained more polyphenols — micronutrients which have been explored for their health benefits.”
The research team believe their “egg-cellent” approach could also have applications in the curing and crystallisation of other materials.