Grading provides a standardized means of describing the marketability of a particular food product. Through the application of uniform grade standards, shell eggs can be classified according to a range of quality characteristics. Buyers, sellers, and consumers alike can communicate about these characteristics through a common language.
USDA has developed quality grade standards
for shell eggs. The standards define and measure quality in terms of the appearance and condition of the shell as well as the interior quality of the yolk and albumen (white). The final quality rating (AA, A, or B) is based on the factor with the lowest rating.
In order for shell eggs to be eligible for an official USDA grade designation, they must be graded by a plant grader and then certified by a USDA grader. Officially graded shell eggs that pass this examination and evaluation process are eligible for the grade shield and may be identified as USDA Grade AA, A, or B. Grading services are provided in accordance with Federal egg grading regulations.
USDA has also developed official weight (size) classes for shell eggs. There are six U.S. weight classes for the consumer grades of shell eggs--Jumbo, Extra Large, Large, Medium, Small, and Peewee. The classes define the minimum net weight per dozen eggs. Graders check shell egg weights during the grading process to ensure their accuracy.