What the Numbers on Your Egg Carton Really Mean

Editoron

If you’ve ever noticed a three-digit number on an egg carton, you may have wondered what it means. Along with the expiration or sell-by date, egg cartons often include other codes that provide useful information.

1. The Three-Digit Julian Date (Pack Date)

The three-digit number (001–365, or 366 in a leap year) is the Julian pack date. It indicates the day of the year the eggs were washed, graded, and packed.

  • 001 = January 1
  • 032 = February 1 (in a non-leap year)
  • 245 = September 2 (in a non-leap year)
  • 365 = December 31

A higher number generally means the eggs were packed more recently.

2. The Plant Code

A code beginning with the letter P followed by several numbers identifies the processing plant where the eggs were packed. This information is used primarily for quality control and food safety, including product recalls.

3. Sell-By, Expiration, or Best-By Date

Depending on where you live, the carton may display a sell-by, expiration, or best-by date. These dates indicate peak quality or the period during which retailers may sell the eggs. They are not always the same as food safety dates.

If eggs have been properly refrigerated (40°F/4°C or below), they often remain safe for 3–5 weeks after purchase, even if the sell-by date has passed.

Does Fresher Always Mean More Nutritious?

Fresh eggs generally have:

  • Firmer whites
  • More rounded yolks
  • Better texture for cooking

However, claims that nutrients such as **choline, lutein, zeaxanthin, or protein decline significantly over a few weeks of refrigerated storage are not well supported by scientific evidence. Properly stored eggs retain most of their nutritional value throughout their recommended storage period.

The Float Test

The float test can estimate an egg’s age:

  • Sinks and lies flat: Very fresh
  • Sinks but stands upright: Older but usually still usable
  • Floats: Large air cell has developed; the egg is old and should be checked carefully. Floating alone does not prove an egg is unsafe. If in doubt, crack it into a separate bowl and discard it if it has an unusual odor or appearance.

Egg Storage Tips

  • Keep eggs refrigerated at 40°F (4°C) or below.
  • Store them in their original carton to reduce moisture loss and odor absorption.
  • Place them on an interior refrigerator shelf rather than in the door, where temperatures fluctuate more.

Simple Avocado Deviled Eggs

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