Cracking the Code on Supermarket Eggs: How Fresh Are They?

You may have often wondered how old the eggs are that you buy from the supermarket. Believe it or not, they could be up to two months old. How do you know? Are they still safe to eat? Find out!

Ever wonder how old those supermarket eggs are that you just bought? Believe it or not, they could be up to two months old. How can you tell, and are they still safe to eat? We checked in with our fresh eggs expert, Lisa Steele, of Fresh Eggs Daily. Here’s what we found out:

Here’s What Fresh Eggs Daily Tells Us:

By law, an egg can be sold for up to 30 days after the date it was put in the carton. And farmers have up to 30 days to go from when the egg is laid to the carton. That means those supermarket eggs can be two months old by the time you buy them. Despite their age, however, the eggs will be fine to eat, just not as fresh, of course (and we can all agree, nothing is better than a farm-fresh egg!). You may find that the yolks won’t be quite as firm and the whites will be more runny, but from a safety standpoint, there are no dangers as long as each egg passes the smell test: if it  doesn’t smell good, toss it! The reason for the runnier consistency is that more air has had the chance to seep through the pores in the shell  — commercial egg processors remove the microscopic protective exterior membrane called the “bloom” which keeps bacteria out. The one plus side to an older egg? It’s easier to peel when hardboiled.

So how can you ensure your store-bought eggs are as fresh as possible?

You have to “crack” the “code.”

On each egg carton, there’s a number printed, from 1 to 365. That number represents the day of the year the carton was filled: 1 being January 1st and 365 being December 31st. Using the code, you can at least tell when the eggs were put in the carton.

For example, a carton with the code 355 means the eggs were put in the carton on the 355th day of the year, or December 11th. If the carton was purchased at the grocery store on January 8th, that means those eggs are at least 28 days old.

Are supermarket eggs fresh?
This carton shows the #355 under the Best By date. That number tells us a lot! Photo used with permission by Fresh Eggs Daily.

Best By, Sell By, Use By Dates

Most cartons will also include a “Best By” date and a “Sell By” date. The “Best By” or “Use By” date can’t be more than 45 days past the packaging date. The “Sell By” or “Expiration” date can’t be more than 30 days past the packaging date.

An interesting test to try to figure out the age of eggs, either store-bought or from your backyard, is to conduct the “Float Test.” Gently submerge the uncooked egg in a glass of water. A very fresh egg will lie on the bottom of a glass of water, while an older egg will start to rise up on one end, and eventually float.

The best way to get the freshest eggs possible is to get them from your own chickens or a local farm. However, if that’s not possible, remember to get in the practice of checking carton dates and codes and at least choose those eggs that are the freshest.

For great tips on raising backyard chickens, be sure to visit the Fresh Eggs Daily web site.

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I have eggs that still have a beautiful golden yolk can i eat them or give them to my dog cause they are floating


What does this date mean?
158. P1442. a

John E Green

Interesting information. You may wish to correct your example, tho, as the 355th day is December 21st, not December 11th.

richard Ourada

When in question, put your egg in water. If it floats, throw it away. If it sinks, eat it. Worked for years on the farm.


I saw a program that showed that when eggs are out of date in the stores. They get sent back to the supplier. Supplier take those eggs, and reincorporate the old eggs back into fresh. So you never know how fresh they are, sad world we live in folks ! Just like that really red meat in the stores. A safe amount of carbon monoxide is added and some other gas. 🙁

Darron Howell

Yep they sure do if it prepacked beef you get bet your last dollar it’s been gassed.If you want good fresh meat go to a store that still has a market that cuts there meat them self. My brother had 5 gro. Stores he had the best meats chicken fresh from the processing plant. It doesn’t get any fresher that that unless your cleaning your on chickens.

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