Eggs-tra ap-peeling.

Membranes. Temperature. Contraction. And how to peel an egg perfectly.

Smiling egg - peeling the perfect egg is about getting the temperature difference right.

1-Minute NomNom

Peeling the shell of an egg perfectly has been the subject of many sites. In a (nut)shell, pun intended, it boils, pun intended again, down to using temperature differences to make the peeling task an easy one.

In the egg are two membranes: an outer shell membrane that sits next to the shell, and an inner shell membrane that sits between the inside of the egg and the outer shell membrane. In between the two membranes, at the bottom of the egg is an air cell or air pocket.

5 days old egg being candled. The air pocket, veins and the chick's eye are clearly visible.

Air pocket is visible at the bottom of the egg

When we boil an egg, it is at a higher temperature than the ambient temperature. As it cools, the inside starts to contract. As the egg cools and contracts, the two membranes contract too and are pulled apart, forming an even larger air pocket. The larger the air pocket is, the easier it is to peel the shell.

That is why websites such as LifehackerSerious Eats, and Momables suggest cooling the egg after you have boiled it. They even go as far as to recommend that we plunge it into ice water!

The air bubble also has another use. It can be used to see how fresh an egg is – find out how in the 1-Minute NomNom “Get fresh“.

egg air bubble peeled

the egg can rest on its base because of the crater left by an air bubble

Feed Me!

How do you get a perfect peel? Share your tips and tricks in the comments below!


Screen Shot 2015-01-10 at 6.02.39 pmLike this? Be eggs-tra ap-pealing and like me to discover more. All you need is a minute a day to explore the world’s marvels through the phenomenon of food!


photos: in order – istockphoto/Bedolaga; depositphotos/Klannekeakulamatiau


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