Pay attention to this date from now on. It’s not an ordinary expiration date.

Eggs are a common food in many homes. They’re a flexible protein source for any meal, and can be cooked in various ways. But the expiration date on egg cartons isn’t straightforward. There’s a Julian date code on the carton that helps you tell if eggs are fresh.

You can find this three – digit code on the side of the carton, near the sell – by date. It’s not a serial number but a date, ranging from 001 (January 1st) to 365 (December 31st). The code shows when the eggs were washed, graded, and packed. Eggs are freshest 4 – 5 weeks after packaging. The USDA allows eggs to be sold up to 30 days after packaging, so store – bought eggs might be a few weeks old.

Older eggs that aren’t rotten are still edible, but they do degrade over time. They lose moisture and carbon dioxide, making yolks more breakable and whites runnier. Also, they’re more likely to cause food – borne illnesses.

Next to the Julian date, there’s a code starting with “P”. This plant code tells you where the eggs were packaged. It’s useful if there’s a recall.

After picking eggs with a recent Julian date and early sell – by date, store them correctly. Put them in the coldest part of the fridge, in their original carton, not on the door. Eggs are usually safe to eat after the sell – by date, as UNL Foods says.