How To Cook the Perfect Boiled Egg, According to Science

Scientists from the University of Naples Federico II have cracked the code for making a perfect boiled egg.

Egg whites and egg yolks start to cook at different temperatures, making it impossible for traditional boiling or sous vide cooking techniques to produce an egg with a fully set white and a still-velvety yolk.

The scientists’ new method, dubbed “periodic cooking”, involves transferring the eggs frequently between hot and cold water during cooking to keep the yolk from overheating. This results in a perfectly cooked egg.

The results are published in Communications Engineering.

How to cook a perfect egg

The perfect boiled egg is a surprisingly elusive food — the proteins in egg yolks denature and thicken at 65°C (149°F), while egg whites require a higher temperature of 85°C (185°F) for perfect cooking. Some chefs have tried to get around this issue by cooking the yolk and whites of the egg separately, but this process requires far too many steps to be practical.

Inspired by their previous work, where the researchers had been applying time-varying conditions to precisely manufacture layered foams of different densities, the team decided to apply the same principles to egg cooking.

They first simulated the egg cooking process inside their computational fluid dynamics software. These simulations suggested transferring an egg between a pot of boiling water and a bowl of lukewarm water (30°C or 86°F) every 2 minutes for a total of 32 minutes.

The researchers then trialed this process manually, first cooking up eggs using traditional soft-boiling, hard-boiling and sous vide cooking techniques for comparison, then using their periodic technique.

Visual and sensory analysis confirmed that the periodic egg retained its runny, creamy yolk while still having a fully-set white.

Further scientific analysis using Fourier transform infrared (FT-IR) spectroscopy confirmed that the protein denaturation and aggregation (i.e., how well the egg part gelled and thickened) seen in the periodic egg reflected the textures expected for an egg yolk cooked at 65°C (149°F) and an egg white at 85°C (185°F).

Analysis using proton nuclear magnetic resonance (¹H-NMR) spectroscopy and high-resolution mass spectrometry (HRMS) revealed that the nutritional composition of the periodic eggs may also outweigh other cooking methods. Specifically, testing found that the periodically cooked yolks contained more polyphenols; a polyphenol-rich diet has previously been linked to disease prevention.  

The researchers believe that their periodic cooking technique could also be exploited for other purposes outside of the kitchen, with periodic thermal treatment being a potential avenue for exploration in all manner of curing, crystallization and materials development processes.

Reference: Di Lorenzo E, Romano F, Ciriaco L, et al. Periodic cooking of eggs. Commun Eng. 2025;4(1):5. doi: 10.1038/s44172-024-00334-w

This article is a rework of a press release issued by Springer Nature. Material has been edited for length and content.