In an episode of Science Friday, cooking geek Jeff Potter has shared his perfect recipe for easy-to-peel hard-boiled eggs. Rather than boiling them under an inch of water, Potter’s method involves steaming them above the water.
When people think of the parts of the egg, they typically remember the shell, whites, and yolk. However, when it comes to peeling, the inner and outer membranes beneath the shell are the most important. They are mostly collagen, and are important for keeping the shell intact. With hard-boiled eggs, the trouble occurs when the shell and the membrane stick to the egg white.
By steaming an egg, the shell and membrane heat up really quickly. By “shocking” it in this manner, the membrane isn’t able to stick to the egg white. Because of this, the worst thing someone can do when hard boiling eggs is to start them in cold water. This gives the shell and membrane plenty of time to cook with the egg, making it stick.
Many people are aware that “shocking” the egg is important, but most believe it has to do with placing the egg in ice-cold water after boiling them. This trick has hardly anything to do with peeling the egg. Instead, this has everything to do with the final shape of the egg. When egg cooks, it expands inside its shell. Allowing the egg to cool down slowly cause the egg white to shrink back toward the top of the egg shell. By “shocking” it in cold water, the egg white doesn’t have time to retract, leaving a nice, round bottom.
For those who would like to try something a bit different, Orbi has a device that allows users to scramble an egg inside its own shell. It may be harder to peel, but the finished product is a golden egg.