Have you ever cracked an egg and noticed two small, white, string-like structures attached to the yolk? These unusual-looking strands are called chalazae (singular: chalaza), and they are a completely natural and important part of a chicken egg.

The chalazae are made from twisted strands of thick albumen, or egg white. They form naturally as the egg travels through the hen’s reproductive system and help keep the yolk positioned correctly inside the egg.

Contrary to what some people believe, the chalaza is not an embryo, blood vessel or sign that an egg is fertilised. It is present in both fertilised and unfertilised eggs. Finding a prominent chalaza is simply evidence of the egg’s normal internal structure.

A typical chicken egg contains two chalazae, positioned on opposite sides of the yolk. They extend from the yolk towards the inner membranes at either end of the egg. Their twisted, rope-like structure acts somewhat like a suspension system, helping to hold the yolk in place.

This is particularly important because the yolk is the nutrient-rich centre of the egg. In a fertilised egg, the developing embryo needs to remain positioned correctly. The chalazae help maintain the yolk’s position within the surrounding albumen while still allowing it to move slightly.

The chalaza is formed from the thick albumen, also called the firm or dense white. As the egg moves through the hen’s oviduct, the albumen is deposited around the yolk. The rotation and movement of the egg help create the characteristic twisted structure of the chalazae.

Interestingly, the chalaza can become less noticeable as an egg ages. The thick albumen gradually becomes thinner and more watery, causing the chalazae to lose some of their firmness and definition. This means that a clearly visible chalaza can often be associated with a fresher egg, although it is not a precise freshness test on its own.

Some people remove the chalaza before cooking, particularly when preparing delicate dishes. However, there is no need to remove it. The chalaza is completely edible and does not affect the taste, safety or nutritional value of the egg.

In fact, its presence is a reminder of just how cleverly an egg is designed. From the protective shell and membranes to the albumen and yolk, every part has a role.

So, the next time you crack an egg and see those little white strings, don’t be alarmed. The chalaza is simply nature’s tiny suspension system, keeping the yolk safely positioned inside the egg.