What Is a Chalaza? | Bon Appétit

I, just like you, am slightly frazzled when I crack an egg and see a spider-web-like string of white attached to the yolk. What is it? And why did this happen to me? There are some silly explanations and theories—maybe it’s the egg’s umbilical cord, or even salmonella, the people say.

So in my grave personal pursuit of finding out what that white stuff is (an eggs-planation, if you will), I spoke to livestock and farm specialist Amy Barkely from Cornell’s Cooperative Extension. Read on for answers.

What is that white stuff?

The white stringy bit of an egg does indeed have a name—it’s called the chalaza, (pronounced kuh-lay-zuh). “It’s essentially egg white protein that has had the water wrung out of it. As the egg clumps into its form, the protein around the yolk will form white strands that attach to both ends of the egg,” explains Barkely. The white strands are twisted in opposite directions and anchor the yolk to make sure it’s centered in the shell. As an egg sloshes around—hey, carrying groceries on the subway isn’t easy—the chalaza will balance the yolk’s movements.

Why does it show up only sometimes?

There are plenty of factors that determine how easily you can see the chalaza—the age of the hen being one of them. “Younger hens tend to produce a more bouncy, obvious chalaza,” Barkely says. “Older hens have weaker, waterier egg whites in general, which makes the chalaza less prominent.”

But the freshness of an egg also impacts the chalaza’s visibility. When an egg sits and matures in storage, the white will begin to break down or degrade. Because of that, the chalaza will disintegrate and become less apparent over time, looking more translucent.

Can I eat it?

Definitely. Although you may be a little put off by the chalaza’s appearance, “it’s a 100% edible part of the natural egg,” Barkely says.

After frying an egg, most of the time you won’t be able to notice the chalaza. It’s difficult to find it in the cooked egg white since they’re the same creamy opaque color. But you might be able to feel the texture—Barkely describes it as “a bouncy ball feeling between your teeth.”

But what if I don’t want to eat it?

If you’d rather not eat the chalaza, simply remove it when the egg is raw.

There are a couple of ways to do this. In the case of a fried egg, where you’d like to keep the egg intact, you can remove the chalaza by pinching it out, using kitchen tools. Barkely shares, “I actually have a friend who’s very, very opposed to them. She has a dedicated pair of tweezers that she uses to pick them off.”

When you want extra smooth whisked eggs, like in the case of custard, a French-style omelet, or silky steamed eggs, you’ll want a fine-mesh sieve (a hack we learned from season two of FX’s The Bear). This technique will catch all the things you might not want—bubbles, eggshell, and the adamant chalaza.

Rise and shine