Removing the shell of boiled egg is so easy but it always annoys me when the shell is sticking to egg white. Small portion of white is wasted every time I prick the shell apart. Shelled boiled egg should have a smooth surface but I often get a bumpy one.
Mom told me, the egg should be soaked in cold or running water immediately after boiling. This will cause an immediate cooling and loosening of shell from the egg white. The bumpy eggs never happened to me again since I followed her advice.
I was still confused though. I wanted to know if the immediate cooling really has effect on egg shelling quality. If it can really loosen the shell from the white. I bought three eggs and boiled them.
I shelled one egg immediately after 15 minutes of boiling. It was too hot so I used a pot holder to hold the egg and a spoon to prick the shell off. No shell stuck to white and the result was good.
I soaked the second egg in a dipper of water immediately. It was cold enough to touch after three minutes. I shelled it and got a silky smooth egg.
The third and last egg. I removed it from boiling water and let it cool by itself. I shelled it and got a silky smooth egg.
The mystery unsolved. More reading and experiment needed.
update as of June 25, 2012. Please refer to sticking shell part two.