Kitchen Mysteries is a weekly exploration of oddities surrounding cooking and food. They could be recipes that fail when they shouldn't, conflicting advice from different sources, or just plain weirdness. If it happens in a kitchen, and you're not sure why, send a tweet to The Food Geek to find out what's happening.
I've heard something from many reputable sources that's meant to be kind of a mini-revolution in food preparation technique. Most recently, it was from Foodimentary on twitter, a great little "learn something about food every day" feed. In any case, one day Foodimentary writes:
The theory goes that, if you crack an egg on a sharp edge, that sharp edge not only breaks the shell, but pushes a piece of shell up into to edge. However, if you crack the egg on a flat surface, the egg does crack, but as nothing is going into the center of the egg, the shell remains on the outside.
This makes a certain amount of sense, and I've been doing it for the past few years, but I've never really gotten the hang of it. I seem to get at least as many egg shell pieces in the egg as before. And as I thought about it more, I've come up with a counter* theory.
You see, just on the inside of the egg is a thin membrane that protects the egg from wee beasties like bacteria and viruses. It also causes problems when you're peeling hard-boiled eggs. What it really does well is to stick to the egg shell itself.
When you crack an egg on a corner, you make a very defined point of breakage. There can be some around the edge, but with all the force concentrated on one line, it's likely that not only will the egg break there, but the membrane will be torn there as well. No matter how many little pieces are created, as long as they are still connected to that membrane, they won't get released into your egg.
When you crack an egg on a flat edge, the egg cracks in many places, and it's unlikely that the membrane will break at a defined point. You either have to force an edge with a finger, or you have to tear the egg apart. With either method of separation, the membrane is going to separate somewhat randomly instead of on a straight line, which increases the chances of allowing a piece of shell to separate from the pack.
Because it's egg nog season, I've been cracking many eggs the past couple of weeks. I've tried both methods, and I have to say that the edge method is easier for me and with no troublesome egg fragments. How about you? Have you switched from edge cracking to flat cracking? How did that work out? Has anyone switched back to edge cracking?