Of course, “fresh is best,” but eating older eggs that are still good isn’t automatically a problem. Eggs that aren’t rotten can be eaten, and “it’s always a shame to waste food.” That said, eggs naturally deteriorate over time. They lose moisture and carbon dioxide, which makes yolks easier to break and whites runnier, and “older eggs pose a greater risk of food-borne illnesses.”

Eggs remain a household staple because they are versatile, affordable, and packed with protein. They work for nearly any meal and can be prepared in countless ways. The confusion usually comes from dates on the carton, which “aren’t as clear-cut as the dates on other items.”

Beyond the sell-by date, cartons include an extra code known as the Julian date. “It looks like a three digit serial number but it’s actually a date.” Julian dates run from “001 to 365,” with 001 representing January 1 and 365 representing December 31.

This code shows when eggs were “washed, graded, and loaded into their cartons.” Eggs are at their best about four to five weeks after packaging. Since the USDA allows eggs to be sold for up to 30 days after packaging, some cartons on shelves may already be weeks old, making the Julian date a useful tool for choosing fresher eggs.