NBC 5 Dallas-Fort Worth
There may be an art to creating the ultimate boiled egg, but scientists say they have cracked the code through mathematics and rigorous experimentation.
While today might not be the best day to test the technique—given the recent surge in the price of U.S. eggs due to an outbreak of bird flu—the result will ensure a soft, but velvet-textured yolk and a set but tender white.
Achieving this balance is notoriously tricky. The reason is that egg whites require hotter temperatures to set than yolks do. Ordinary hard-boiling can set the yolk dry and chalky, whereas using lower temperatures leaves the whites not quite cooked and gelatinous.
In order to solve this cooking problem, researchers boiled as many as hundreds of eggs and used mathematical formulas to model how the heat circulates through the egg and how it affects texture and doneness.
The Solution: Periodic Cooking
Their solution? A process they call periodic cooking.
In this method, eggs are steamed in a steamer basket and alternated every two minutes between two bowls of water—one at a rolling boil, the other at 86°F (30°C) lukewarm—totaling 32 minutes. The eggs are then cooled under a flow of cold water and peeled.
“You can try it at home, too, with half a dozen or so eggs,” said chemist Gregory Weiss of the University of California, Irvine, who did not work on the study.
To study author Emilia Di Lorenzo at the University of Naples Federico II, the yolk comes out so velvety and rich, “you can almost spread it, like on a piece of bread.”
To test the outcome, researchers tested the chemical composition of the eggs and conducted a taste test with a panel of eight volunteers, pitting the novel method against traditional boiling techniques.
The findings were published Thursday in the journal Communications Engineering.
Although the process is longer than boiling eggs in a pot, University of Minnesota food scientist Joanne Slavin, who wasn’t affiliated with the study, said the reward is well worth it.
“This is a slower process to get a better outcome,” Slavin said. “The texture makes all the difference.”
