[Super_Dave_D]

Why are peeling fresh eggs shells so difficult?

With eggs that are just a day or two old, the membrane beneath the shell sticks tightly to the shell making peeling the egg almost impossible. After a few days in the refrigerator the egg becomes easier to peel. Why is this? In fresh eggs the albumen sticks to the inner shell membrane more strongly than it sticks to itself because of the more acidic environment of the egg. The white of a freshly laid egg has a pH between 7.6 and 7.9 and an opalescent (cloudy) appearance due to the presence of carbon dioxide. After the protective coat is washed off the egg shell the egg becomes porous and begins to absorb air and loose some carbon dioxide contained in the albumen. This reduces the acidity of the egg which causes (after several days in the refrigerator) the pH to increase to around 9.2. At higher pH the inner membrane does not stick as much to the albumen so the shell peels off easier. In addition, as the egg gets older it will shrink and the air space between the egg shell and the membrane will get larger.

Research shows that the reduced acidity helps with peeling. The tradeoff, however, is that in older eggs the yolk tends to move further from being centered. This happens because the white gets thinner and is less able to hold the yolk in place. The best compromise is to use eggs that have been stored on their sides in the refrigerator for 7 to 10 days.

Tips on Peeling Boiled Eggs :

What is the best way to peel a boiled egg so the egg white does not stick to the shell? Here are several responses, although all bets are off for eggs only a couple days old.

>>> After boiling, pour off the hot water, shake pan back and forth to crack the shells. Cover eggs in cold water and let set for a couple of minutes. Leave water and eggs in pan and peel, using water to rinse away excess shells.

>>>Or, take the egg from boiling water and immediately run cold water on it. Peel the egg under cold running water starting with rounded top where the air pouch is.