Scientists Say They've Discovered How to Cook the Perfect Boiled Egg—and It May Be Healthier, Too Here's how you can do it at home
Researchers say they've discovered a way to boil an egg that cooks both the white and yolk to perfection
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- In a new study, scientists developed a method to boil an egg that may cook both the yolk and white to perfection, which enhancing its nutritional content.
- The method, called "periodic cooking," involves alternating the egg between boiling and cold water every two minutes for 32 minutes total.
- Experts explained why this method may make the egg more nutritious and provided tips for trying periodic cooking at home.
For years, the culinary community has debated about the right way to boil an egg. But scientists have now discovered a method that they say may cook both the yolk and white to perfection—and potentially enhance the egg's nutritional content.
It’s called “periodic cooking,” and a new study details its benefits and what it entails.
Here’s what researchers discovered—plus, how to try it at home if you're feeling extra motivated.
Fixing a Problem
The study, published in the journal Communications Engineering, was designed to solve a problem: The yolk and egg white in chicken eggs cook at different temperatures. The egg white (a.k.a. the albumen) cooks at 185 degrees Fahrenheit, while the yolk cooks at 149 degrees Fahrenheit.
That can make it tricky to get a well-cooked hard-boiled egg without overcooking the yolk. “Some high-level chefs cook their eggs by separating yolk and albumen and cooking them at their corresponding optimal temperatures to reach their respective ‘optimal’ textures,” Emilia Di Lorenzo, study co-author and a professor of mathematical methods for economics, finance, and actuarial sciences at the University of Naples Federico II, told Health.
So, Di Lorenzo and fellow researchers wanted to see if there was a way to cook both parts of the egg properly without cracking the egg open. “It was a matter of final taste, surely, but it was also a matter of science. The best way to start a project,” Ernesto DiMaio, PhD, study co-author and researcher at the University of Naples Federico II, told Health.
Testing Cooking Methods
Di Lorenzo, DiMaio, and other researchers developed a computer model to create simulations showing them the best way to cook the yolk and whites without losing taste and texture.
They discovered that the ideal method is to move an egg between a pan of boiling water at 212 degrees Fahrenheit and a bowl of water at 86 degrees Fahrenheit.
With this method, called “periodic cooking,” the egg should be moved between the water containers every two minutes for 32 minutes.
The researchers also tried out the strategy in real life and compared it to the results for hard-boiled, soft-boiled, and sous vide eggs. (Sous vide, in case you’re unfamiliar with it, is a cooking method that involves putting food in a vacuum-sealed bag in water and cooking it at a well-controlled low temperature.)
Once the eggs were cooked, they were analyzed for texture and sensory qualities. Nuclear magnetic resonance and high-resolution mass spectrometry were also used to examine chemical properties.
The researchers discovered that eggs prepared through periodic cooking—alternatively subjecting the egg to high and low temperatures—had a soft yolk and egg white consistency between sous vide and a soft-boiled egg. DiMaio said the method allowed for the “best possible texture: The albumen is fully set, while the yolk is super creamy.”
Periodic cooking kept the egg yolk at a consistent temperature of about 153 degrees Fahrenheit, while the egg white was between 86 and 212 degrees Fahrenheit.
Chemical analysis also found that the periodically cooked egg yolks contained more polyphenols, which are micronutrients that can protect cells from damage and inflammation and potentially reduce disease risk.
Why More Polyphenols?
The researchers aren’t sure why this cooking method may cause an egg to have more polyphenols. “Our guess is that cooking at a temperature that is so close to the protein’s denaturation temperature helps in preventing loss of nutrients,” DiMaio said.
Jessica Cording, RD, author of "The Little Book of Game-Changers," told Health that some polyphenols are more sensitive to heat than others. As a result, it simply could be that the polyphenols found in egg yolk are more likely to be present in greater numbers if the yolk isn't overcooked.
“Excessive heat can also trigger oxidation, reducing the bioavailability of these compounds,” Darin Detwiler, LPD, author of the book "Food Safety: Past, Present, and Predictions" and a professor at Northeastern University, told Health. “By avoiding prolonged exposure to extreme temperatures, this method may help retain more of these valuable nutrients.”
However, Cording stressed that even if you boil eggs the regular way, “you’re still going to get a lot of nutrients.”
Is This Cooking Method Safe?
If performed correctly, there’s no reason to worry about your egg being undercooked, Ellen Shumaker, PhD, director of outreach for the Safe Plates program at North Carolina State University, told Health. “Given the amount of time that this study cooked the eggs in total, I do not have food safety concerns,” she said.
The United States Department of Agriculture recommends that hard-boiled eggs be cooked in hot water that has been boiled and left to sit for 12 minutes for medium-size eggs, 15 minutes for large eggs, and 18 minutes for extra-large eggs.
“Given that the yolk is maintaining [152.6 degrees] for 32 minutes, this time and temperature relationship is sufficient to kill off salmonella, which is the pathogenic bacteria of concern here,” Shumaker said.
How to Try Periodic Cooking at Home
Periodic cooking isn’t the easiest or fastest way to boil an egg, and that’s a fact that the researchers acknowledge. “We recognize that this process takes time; however, it is a good way to treat yourself,” Di Lorenzo said.
If you want to attempt it, Shumaker recommends grabbing a food thermometer to ensure the correct temperature. (“Without precise temperature control, there’s a potential risk of bacterial survival,” Detwiler pointed out.)
Then boil water on a stove and place a bath of what DiMaio calls “cold water” next to it. “Please try to keep the cold water at 86 degrees Fahrenheit throughout the cooking process,” DiMaio said. “This means that you will have to put some fresh water inside the cold water bowl from time to time.”
Then, place an egg in the boiling water for two minutes before moving it to the cold water bowl for two minutes. Repeat this process eight times.
More tips from the researchers:
- Gently scratch the top of the egg with a knife to make it more porous and avoid cracking the shell when you put it in hot water.
- Try to gently stir the egg while it’s in the cold water bowl. “This will prevent the yolk from falling down due to gravitational forces,” Di Lorenzo said.
- Use medium-sized eggs (about 68 grams each). “If you use bigger eggs, you might have to adjust the process, using slightly longer timings—20-30 seconds should be enough,” DiMaio said.
If you want to speed up the process, Di Lorenzo suggests increasing the cold water temperature to 104 degrees Fahrenheit and doing fewer cycles. “We found our optimum, but you can play around and find yours,” she said.
This story originally appeared on: Health News - Author:Korin Miller
