Column: What to look for when buying eggs

By Roland Mader

Dairy and Egg Program Manager,

Arizona Department of Agriculture

Expiration dates and grade of the eggs

What do all the numbers listed on the side of my egg carton represent? Almost all cartons, overwrap, and types of consumer packages sold in Arizona require legible lot numbering on the consumer package, there are some exemptions for very small producers.

The lot number is the consecutive day of the year in which the eggs were packed into the carton, and consists of three digits, such as 042, 155, 267, etc. Since the lot number represents the consecutive day of the year, eggs packed into the container on January 1 would be listed as 001. The other numbers are the packaging plants number and the expiration date of the eggs. The expiration date is specific to the grade of the egg Grade AA is the highest grade and so they are the freshest eggs they usually have an expiration date prefix “sell by” and this date may not exceed 24 days vs the Grade A eggs expiration date prefix is usually “Best By” and may be up to 45 days. Grade B is the lowest consumer grade and does not require to have a printed expiration date on the carton.

Are eggs safe to eat after the Use By or Sell By date has expired?

The Use By or Sell By dates stamped on the end of an egg carton denotes the period of optimum egg quality and guarantees to the customer that they receive the grade that is labeled on the carton.

As eggs age, the yolk membranes and tissues weaken and/or moisture is absorbed from the albumen (white). As a result, the yolk begins to flatten and the albumen becomes watery. This is indicative of a Grade B, quality egg.

For baking purposes, a higher quality egg (Grade AA or A) is preferred.

For hard-boiling purposes, a lower quality egg (Grade B) is preferred.

Additionally, retailers utilize the Use By or Sell By dates for stock rotation or inventory control. Expired eggs are not allowed to be sold.

Why do some egg cartons contain the AZDA grademark or USDA grademark (shield) on them, while others do not?

Aren’t all eggs graded? Eggs in cartons that do not contain the AZDA or USDA grademark (shield) are required by the Arizona Administrative Code to meet USDA’s facility, sanitation, and labeling requirements (7 CFR Part 56) and do undergo the in house grading and certification process in accordance with the U.S. Grade Standards, Grades, and Weight Classes for Shell Eggs (pdf) (AMS 56). However, for those packages no inspector is on duty at the time that the eggs are being packaged to ensure all eggs meet the standard and requirements. Eggs without a shield get inspected during unannounced visits at the producer and in retail stores.