albumen index

A measurement of egg quality based on the behavior of the egg white when a broken egg rests on a flat surface. The thick albumen of a fresh egg stands tall in a firm mound around the yolk, while in an older egg it spreads thin and watery. The index compares the height of the thick white to its width, with higher values indicating fresher, higher-quality eggs. It correlates with the Haugh unit, the industry’s standard freshness score, and both decline as carbon dioxide escapes through the shell during storage and the white’s protein structure loosens. Egg graders and quality laboratories use these measurements to verify freshness claims, set sell-by dates, and compare the keeping quality of different production and storage systems.