chalaza

Chalaza are two twisted, cord-like structures of egg white that extend from opposite ends of the yolk toward the shell membranes. They are most noticeable in fresh eggs and become less visible as the egg ages.

Structure and formation: The chalazae consist of protein filaments within the albumen, anchored to the chalaziferous layer around the yolk and to the inner shell membranes. They form during egg development as the yolk moves within the thick and thin portions of the white.

Function: Chalazae help center and anchor the yolk within the egg, providing stability during handling and movement. By suspending the yolk, they help protect it from contact with the shell and potential damage.

Freshness and appearance: In very fresh eggs, chalazae are prominent and easily seen. Over time, they may become thinner and less distinct, or appear to disappear. Their presence is not a definitive measure of safety or quality, but strongly pronounced chalazae often indicate freshness.

Culinary notes and safety: The chalazae are edible and safe to eat. Some cooks remove them for aesthetic reasons or in recipes that require a smooth texture, such as custards or certain sauces. Removal is optional and does not affect the egg’s safety when stored properly.

Occurrence: Chalazae are common in eggs laid by many birds, not just chickens, and are a normal feature of fresh eggs in many species.