Hard-steamed egg

To me, the most challenging thing about a hard-boiled egg is not cooking it, but smoothly peeling it.

While there are many ways to approach this challenge, I recommend not to boil the egg, but to steam it.  Steam for 14 minutes, then transfer to an ice-water bath (at least 50:50) for 15 minutes (Kamozawa and Talbot).

The shells almost fall off, leaving  a glisteningly smooth surface (click on the image and notice the detail in the window reflection)

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With these timings, the yolk is cooked through, without discolouration around the outside of the yolk.

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Its a reliable and reproducible method:

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So, the term hard-boiled has to go, because they are not boiled. Hard-steamed it is for me from now on…

Eggs can also be steamed in a pressure cooker. This one below was cooked for 5 minutes at full pressure, cooled down rapidly and then put in an ice-bath for 15 minutes. Notice the creamy soft yolk. It is more delicate and a little more difficult to peel.

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While steaming works, I have been unable to find out why.

There seems to be a difference if the egg is boiled in water, so I presume it has something to do with the porosity of the shell. Perhaps when boiled, water can migrate into the egg before the white has had a chance to set, hydrating and swelling it so that it binds more strongly to the inner membrane and shell.

The ice-bath period might be a consideration also. If water were to migrate through the shell into the now-cooked egg, it could help separate the egg from its shell. This could be helped if the egg shrinks a little with cooling. Although this is presumably common to both steamed and boiled eggs.