Arts: Food Explainer: Why Are Some Boiled Eggs Easier To Peel Than Others?

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Brow Beat Food Explainer: Why Are Some Boiled Eggs Easier To Peel Than Others? By Nadia Arumugam Posted Thursday, Sep 20, 2012, at 12:45 PM ET The third entry in a new occasional series in which we demystify all manner of gustatory conundrums and culinary puzzles. If you have a food-related question you'd like answered, see the email address provided below. Peeling hardboiled eggs is a roll of the dice. Some eggshells slip right off the white, but others cling desperately, no matter how you pick at them. Why are some eggs easier to peel than others? As a rule, the fresher the egg, the more difficult it is to peel cleanly. The albumen (white) of a just-laid egg contains a store of dissolved carbon dioxide, a weak acid. (CO2 is what makes very fresh raw egg whites appear cloudy.) Over time, the gas exits the egg through thousands of tiny pores in the shell. As this happens, the pH of the white gradually increases, making it less acidic. Why does acidity matter? The inner membrane of an egg—that translucent skin that envelopes the albumen—is made partly from a protein called keratin (also found in hair and nails), which is tougher in an acidic environment.  At the lower pH of a fresh egg, the proteins in the egg white bind tightly to the keratin in the membrane during the cooking process, which makes it nearly impossible to remove the shell without chunks of white attached. Up the alkalinity, and the keratin softens, leading to a looser bond between the white and the membrane—which means hassle-free peeling.  An average commercially produced egg ... To continue reading, click here. Join the Fray: our reader discussion forum What did you think of this article? POST A MESSAGE | READ MESSAGES Also In Slate When Did Bare Breasts Become Taboo? The World's Least-Popular Four-Digit PIN: 8068 Parents, Don't Panic Over West Nile	Advertisement
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