How to Tell If an Egg is Bad: The Ultimate Guide


Dear Asensio, welcome to our article on how to tell if an egg is bad. Whether you’re a professional chef or a home cook, knowing how to determine if an egg is safe to consume is essential to keeping yourself and your loved ones healthy. This guide will provide you with all the information you need to identify bad eggs and protect yourself from foodborne illnesses.

In this article, we’ll cover everything from how to read expiration dates on egg cartons to conducting the infamous “float test.” We’ll explore why eggs go bad and how you can reduce the risk of spoilage. We’ll also answer frequently asked questions about egg freshness and provide you with a comprehensive table that outlines how to tell if an egg is bad. So, let’s get started!

What Causes Eggs to Go Bad?

Before we dive into how to tell if an egg is bad, let’s examine what causes eggs to spoil in the first place. Eggs are perishable foods that are vulnerable to bacterial contamination. As soon as an egg is laid, it begins to lose moisture through the shell, which causes its contents to shrink and air pockets to form. This air space grows larger over time, and as it does, the egg’s freshness deteriorates.

Another factor that causes eggs to spoil is the presence of bacteria. Fresh eggs are protected by a natural coating called the “bloom,” which acts as a barrier to bacteria. However, as the egg ages, this coating wears off, making it more susceptible to contamination. When bacteria enter an egg, they break down its proteins and create gas, which causes the egg to smell bad and taste rancid.

How to Read Expiration Dates on Egg Cartons

One of the easiest ways to determine if an egg is past its prime is to check the expiration date on its carton. In the United States, all egg cartons are required to have a “Sell By” date stamped on them, which indicates the last date the eggs should be sold. This date is usually set at 30 days from when the eggs were packaged.

However, the expiration date is not a foolproof indicator of egg freshness. Eggs will typically remain safe to eat for up to three weeks after the “Sell By” date has passed, as long as they have been properly stored. So, while it’s a good idea to use eggs before their expiration date, it’s not always necessary.

The Float Test

If you don’t have access to an expiration date, or if you’re unsure if an egg is fresh, you can conduct the “float test” to get an idea of its age. To perform this test, fill a large bowl or glass with water and gently place the egg in it. If the egg sinks to the bottom and lays flat on its side, it’s fresh. If it stands upright on the bottom, it’s still safe to eat, but it’s not as fresh. If the egg floats to the top, it’s no longer good and should be discarded.

The Sniff Test

Another easy way to tell if an egg is bad is to use your nose. Fresh eggs should have no odor, while rotten eggs will have a sulfurous smell that’s hard to miss. If the egg smells bad, it’s best to err on the side of caution and throw it away.

The Crack Test

If you’ve already cracked an egg open and you’re unsure if it’s fresh, you can examine its contents for signs of spoilage. Fresh egg whites will be clear and thick, while fresh yolks will be round and high. If either the white or yolk is runny or watery, or if they have a strange color or odor, the egg is no longer good and should not be consumed.

Storing Eggs Properly

The best way to ensure that your eggs stay fresh for as long as possible is to store them properly. Eggs should always be kept in the refrigerator, as room temperature speeds up their deterioration. They should be stored in the carton they came in, rather than in a separate container, as this helps to protect them from moisture and bacteria.

It’s also important to handle eggs with care, as they can be easily damaged. Avoid cracking them against hard surfaces, and instead, tap them gently against the edge of a bowl or counter. Don’t wash eggs before storing them, as this removes their natural protective coating.

Table: How to Tell If an Egg Is Bad

Indicator Fresh Egg Not as Fresh Bad Egg
Expiration Date Before “Sell By” Date After “Sell By” Date, but less than 3 weeks After 3 weeks
Float Test Sinks to Bottom Stands Upright on Bottom Floats to Top
Smell Test No Odor Odorless or Slightly Musty Sulfurous or Rotten Smell
Crack Test Clear and Thick Whites, Round and High Yolks Thinner Whites, Flatter Yolks Runny or Watery Whites or Yolks, Strange Color or Odor


1. Can You Eat Eggs Past Their Expiration Date?

Yes, eggs can be safe to eat for up to three weeks after their expiration date, as long as they are properly stored and do not show any signs of spoilage.

2. Can You Freeze Eggs?

Yes, eggs can be frozen for up to 12 months. However, they must be removed from their shells first and stored in airtight containers or freezer bags.

3. How Can You Tell if an Egg is Fresh Without Breaking It?

You can tell if an egg is fresh by conducting the float test, which involves placing it in a bowl of water. Fresh eggs will sink to the bottom and lay flat, while older eggs will stand upright or float to the top.

4. How Do You Know if an Egg is Safe to Eat?

An egg is safe to eat if it is fresh and has been properly stored. You can determine if an egg is fresh by using the float test, the sniff test, or by examining its contents after cracking it open.

5. What is the Difference Between Cage-Free and Free-Range Eggs?

Cage-free eggs come from hens that are not kept in cages, but may still be confined to indoor pens. Free-range eggs come from hens that are allowed access to the outdoors, where they can forage for food and engage in natural behaviors.

6. Are Brown Eggs Healthier Than White Eggs?

No, the color of an egg’s shell has no bearing on its nutritional value or taste. The only difference between brown and white eggs is the breed of hen that laid them.

7. Can You Cook or Bake with Bad Eggs?

No, you should never cook or bake with bad eggs, as they can harbor harmful bacteria that can cause foodborne illness.

8. How Long Do Hard-Boiled Eggs Last?

Hard-boiled eggs can be stored in the refrigerator for up to one week.

9. Can Eating Raw Eggs Make You Sick?

Yes, consuming raw or undercooked eggs can increase the risk of salmonella infection, which can cause diarrhea, fever, and abdominal cramps.

10. Should You Wash Eggs Before Using Them?

No, you should not wash eggs before using them, as this can remove their natural protective coating and increase the risk of contamination.

11. How Should You Dispose of Bad Eggs?

You should dispose of bad eggs in a sealed plastic bag, and then place them in the trash. Do not compost or feed bad eggs to pets or livestock.

12. Can You Smell if an Egg is Bad Before You Crack It?

Yes, bad eggs will often emit a sulfurous or rotten smell even before they are cracked open.

13. How Can You Prevent Eggs from Going Bad?

You can prevent eggs from going bad by storing them properly in the refrigerator, handling them with care, and using them before they reach their expiration date.


In conclusion, knowing how to tell if an egg is bad is crucial for maintaining good health and avoiding foodborne illnesses. By using simple tests like the float test and sniff test, you can easily determine if an egg is fresh and safe to eat. Proper storage and handling of eggs can also help to prevent spoilage and extend their shelf life.

It’s important to remember that while expiration dates can be helpful, they are not always accurate indicators of egg freshness. By using the information provided in this guide, you can become an expert at identifying bad eggs and keep yourself and your loved ones safe.

So the next time you’re in the kitchen, make sure to take a few minutes to check your eggs before using them. Your stomach will thank you!

Closing Statement with Disclaimer

We hope that this guide on how to tell if an egg is bad has provided you with the information you need to keep yourself and your loved ones safe. However, it’s important to note that this article is for informational purposes only and should not be taken as medical or dietary advice. If you have any concerns about the safety of your food or any health-related issues, please consult a qualified healthcare professional.