When it comes to whether or not eggs can expire, the short answer is, yes. Eggs, just like all animal proteins in their original form, will eventually go bad. But how long do you have until they do? How will you know when they’re bad? And how do you store them to keep them fresher longer? Read on to crack the case.

Where should you store your eggs?

In the fridge or out of the fridge? That is the question. The answer generally depends on whether or not you’re buying commercially-produced eggs. In the United States, the US Department of Agriculture requires all commercially produced eggs to be washed and refrigerated before they can be sold in grocery stores. This is different from how eggs are handled in most of the world, but the USDA takes this additional step to reduce the risk of salmonella poisoning. 

When eggs are washed by USDA standards (in a sanitizing solution), a natural protective layer on the outside of the egg gets washed away. So, although the egg is clean, it’s also more susceptible to bacteria moving through the shell. It’s like taking a rain-fly off a tent — still protected from the elements, but it’s easier for water to get in. That’s why we refrigerate eggs — to reduce the risk of bacteria traveling from the outside of the shell to the inside (and then to you, the consumer). 

If refrigerated eggs are left out at room temperature, condensation will form on the outside of the egg. That moisture, combined with increased susceptibility to bacteria at room temperature, can help facilitate the transfer of bacteria through the shell. For this reason, the USDA recommends you do not leave previously refrigerated eggs outside of the fridge for more than two hours. 

The bottom line is this: If you bought your eggs from a refrigerator, keep them refrigerated until you use them.

How long do eggs last in the fridge? 

The general consensus on food safety from the USDA is that raw eggs in the shell will last for three to five weeks when properly refrigerated. 

That three to five-week shelf life starts from the moment you purchase the eggs, not from their pack date (the date they're packaged). So, just like most grocery store products with printed expiration dates, it’s likely they’ll be good past the date listed on the egg carton. These dates are determined by the manufacturer and meant to communicate freshness, not necessarily when something will spoil. 

Unlike other animal proteins whose shelf-life is extended after being cooked, cooking actually shortens an egg’s lifespan. Hard boiled eggs last for just seven days post-boil, as opposed to the three to five weeks you get from raw eggs. This is because cooking further degrades the egg’s shell, leaving it more susceptible to bacterial penetration.

How long do eggs last outside of the fridge?

If you’ve got your own backyard chickens or are purchasing unrefrigerated, unwashed eggs from the farmers’ market, they’ll generally remain good for two to three weeks when stored outside of the fridge. 

Although the USDA does not provide official guidance on this, the general consensus is that if you store eggs outside of the fridge, it’s best practice to keep them in a place where the temperature will remain as consistent as possible. That means keeping them out of direct sunlight and away from the stove. If your pantry or cupboard is in a relatively cool part of your house, both are great options for egg storage. 

Previously unrefrigerated eggs can be refrigerated. Just make sure they stay that way. Moving eggs in and out of refrigeration increases the likelihood that bacteria will pass through the shell, especially once they’ve been washed. So make your choice, and stick with it.

How to tell if eggs have gone bad

If you’re within the three to five-week range but are still concerned that an egg might have gone bad, there are a few things you can do to determine whether or not it’ll still be safe to eat. The most common is the float test — which is exactly what it sounds like. You place an egg into a cup of water, and if it sinks to the bottom, it’s still good to eat. If it floats, maybe not so much. 

According to the USDA, just because an egg floats doesn’t mean it’s rotten — it just means it’s a less fresh egg. As eggs age, air enters the egg through pores and enlarges the egg’s air cell, making it more buoyant in water. 

A better way to determine whether an egg is still safe to eat is to crack it open and examine what’s inside. An important tip to remember: If you’re baking something or are going to cook eggs, don’t crack a questionable egg directly into your other ingredients. Crack it into a separate bowl; that way, if it does end up being bad, you won’t ruin whatever you’re working on. 

Once you’ve cracked your egg, there are a few things to look and smell for. First of all, if you crack into your egg and it has a sulfur smell, you can stop right there. No additional inspection is needed — this egg has gone bad. Rotten eggs start to give off a sulfuric smell because they create hydrogen sulfide as they decay. Once you smell that, it’s game over. Just toss the egg. 

Egg yolks won’t tell you too much about freshness, but an egg white can inform your detective work: If the egg white is cloudy, that’s a good sign. A cloudy white indicates a younger, fresher egg. The clearer the egg white, the older the egg. If the egg white appears pink or iridescent, take it as a sign that the egg’s gone bad. Pseudomonas bacteria gives the egg white that color, and although it’s rare, it’s harmful to humans. It can be pretty but dangerous, so throw it away.

As always, if you have doubts, it’s best to err on the side of caution and throw away eggs you’re nervous about. Eating eggs that have spoiled can cause food poisoning and lead to some pretty undesirable side effects (vomiting, diarrhea, fever, cramps), so trust your senses (especially smell), and get rid of anything you don’t think is good.

What to do with bad eggs

Your rotten eggs don’t have to be a total bummer. With Mill, you can give your spoiled eggs a second life

Sources:

1. U.S. Department of Agriculture, Food Safety and Inspection Service: “Shell Eggs from Farm to Table.” November 14, 2019. https://www.fsis.usda.gov/food-safety/safe-food-handling-and-preparation/eggs/shell-eggs-farm-table

2. U.S. Department of Agriculture: “Should eggs be washed before they are used?” February 23, 2024. https://ask.usda.gov/s/article/Should-eggs-be-washed-before-they-are-used

3. U.S. Department of Agriculture: “How long can you keep hard cooked eggs?” March 22, 2023. https://ask.usda.gov/s/article/How-long-can-you-keep-hard-cooked-eggs

4. Business Insider: “Why eggs have to be refrigerated in the US but not Europe and the best places to store them.” April 22, 2022. https://www.businessinsider.com/guides/health/diet-nutrition/do-eggs-need-to-be-refrigerated

5. Egg Info: “How to store eggs.” https://www.egginfo.co.uk/ways-to-cook/general-tips/how-store-eggs

6. U.S. Department of Agriculture: “What does it mean when an egg floats in water?” October 4, 2023. https://ask.usda.gov/s/article/What-does-it-mean-when-an-egg-floats-in-water