The white string is called the chalaza (kuh-LAY-zuh). It’s a naturally occurring cord made of protein that helps keep the yolk centered inside the egg white.
You can think of the chalaza as the egg’s built-in stabilizer. As the egg moves around, the chalaza helps protect the yolk from bumping against the shell and getting damaged. Most eggs contain two chalazae, one on either side of the yolk, although only one is usually easy to see.
What the Chalaza Reveals About Freshness
The chalaza can also tell you something about the egg’s freshness.
In fresh eggs, the chalaza appears thicker, firmer, and more visible. As the egg ages, it gradually becomes thinner and less noticeable. That means a clearly visible white strand is usually a good indicator that the egg is fresh and has been stored properly.
