The average American consumes 250 eggs per year, so you’ve probably thought about the dozens of different ways to cook them, from scrambling to poaching. But you probably haven’t given much thought to the white string attached to your egg yolk. Maybe you never even noticed it. But if you have, you can’t unsee it. So what are those disturbing white stringy things floating in raw eggs? They’re not what you think. Contrary to popular belief, that white thing floating in raw eggs is not a baby chicken’s umbilical cord. It’s not chicken sperm or a beginning embryo either. (Fun fact: Most commercially produced chicken eggs are unfertilized.) It’s a chalaza—pronounced cuh-LAY-zuh—and it’s totally normal and safe to eat.
If you study the anatomy of an egg, you will notice two twisted strands on both sides of the yolk connected to the inside of the eggshell—and that’s what you’re looking at when you see those snot-looking stringy bits. The chalazae (plural) are rope-like structures made of protein that act as a support system for the yolk. It keeps the yolk suspended in the center of the egg and safe from pressing against the shell or settling on one side of the egg.
When cracking an egg, there’s really no need to remove the chalazae. They’re OK to eat, and once cooked, the strings disappear. It won’t interfere with cooking, unless you’re whipping up custard or curd, in which case the eggs should be strained for an extra smooth texture. Simply pass them through a strainer or use your fork to pick out the chalazae.
Sure, it looks weird, but you should actually appreciate the chalaza: It’s a sign that an egg is fresh and safe to eat. The visibility of chalazae makes it easy to test the freshness of eggs. The more prominent the string is, the fresher the egg. Chalazae tend to disappear as an egg ages, so if you don’t see at least one string in your raw egg, it’s likely growing stale. More chalazae, fewer problems, really.