The Secret Meaning Behind the Numbers on Your Egg Carton

An egg carton's expiration date is not as reliable as it seems. Here's how to tell if eggs are fresh.

Chances are you almost always have eggs in your fridge. Whether baked, scrambled or poached, they’re one of the most versatile items on the grocery list. You might think the best way to pick a carton is by checking the grade, size and expiration date—but there’s a secret behind how long eggs can sit out, how to store eggs and a more efficient way to tell how fresh your eggs are.

Interested? Keep reading.

How to decode your egg carton

On the side of your egg carton, right by (or below) the “Sell by” date, you’ll see a three-digit code. No, it’s not an arbitrary serial number; it’s the Julian date, your fail-safe guide to fresh eggs.

Ranging from 001 to 365, the Julian date represents the day the eggs were packaged. Each code corresponds to a day in the year, so 001 would be Jan. 1 and 365 would represent Dec. 31. Once the eggs are packaged, they’ll keep in your fridge for four to five weeks. Psst: Here’s how long your other grocery staples will last.

According to the U.S. Department of Agriculture, eggs can be sold for up to 30 days after they were packaged. So even if they’re in stock and not expired, they might be weeks old. Eew! (If all this is making you wonder why egg yolks are different colors, we have the answer.)

So why does it matter?

It’s obvious newly packaged eggs taste better, but an egg’s quality can significantly deteriorate over time. As an egg ages, it loses moisture and carbon dioxide, making the whites thinner and the yolk more susceptible to breaking. And when you eat old, expired eggs, your risk of getting a foodborne disease from them increases.

As for the code starting with a “P” right next to the Julian date? That’s the plant code, which represents where the eggs were packaged. If there’s an egg recall, the plant code will determine whether your carton is included.

Look, we know how stressful grocery shopping can be, but checking the Julian date is an extra step worth taking. If you don’t want to whip out your calendar and calculator (we don’t blame you), here’s a general rule of thumb to follow: If you’re buying eggs in early to mid January, look for lower numbers (015 will be significantly fresher than 364). If you’re buying eggs later in the year, look for the highest number possible.

Now that you know how to select your eggs, the next step is to break them. Why not try these tasty hacks for awesome scrambled eggs? Bon appétit!

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Taste of Home
Originally Published on Taste of Home

Kelsey Mulvey
Kelsey Mulvey is a New York–based writer. She has been published in several outlets, including the Wall Street Journal, Time Out New York, and