The Mystery of the Exploding Eggs

Young Master Julien Slate-Aussoleil
holds the explode-o egg so Mom
can take an out-of-focus photo.

A couple of whiles ago, I was working on a book called Scratch (written by Maria Rodale, of the Rodales), in which I learned that to get really consistently peelable eggs, you steam them. Genius! And I've been doing that ever since.

But every so often I would get what I call a "crater egg." It appeared that for some reason the air inside the egg couldn't get out (eggshells are porous, n'est-ce pas?) and pushed the egg white up against the shell at the opposite end, leaving an egg-white crater behind. Net result = the most unpeelable egg you'll ever meet, times a million.

Then, even weirder, some eggs would simply explode in the steamer, with loud (relatively speaking) egg bangs. Of course these were beyond peeling: They needed to be scooped out of the shell.

Why, why? My perfect system! What was wrong with it?

Research on the Google Interwebs Machine.

Fake Egg Bloom. Read on

As an egg emerges from the hen, it gets coated with a thin layer of something called the cuticle or "egg bloom," which seals the pores of the egg, protecting it from anything getting to it while it waits to be hatched. However, unless you raise your own chickens, any egg you've ever purchased has had this bloom washed off.

Some egg producers replace the natural cuticle with a coating of mineral oil or wax* to increase the shelf life. In addition to keeping the bad things out, the coating prevents the egg from "respiring"—a process that over time introduces more air into the egg and eventually makes it go bad. (This is why you can test the age of an egg by seeing if it floats in water.) When you cook an egg in boiling water, the minute you immerse the egg, the hot water melts the wax off (though this is just my guess). But with steam, apparently, not so much.

However, the American Egg Board claims that only 10% of producers actually coat their eggs, so I guess it's just the luck of the draw.

*Anyone who has ever stocked a sailboat's pantry in preparation for a long cruise also knows this trick. With limited fridge space on a small boat, eggs are one thing you can keep at room temp, as long as you dip the eggs in paraffin.