7 Shocking Ways To Tell If Your Eggs Have Gone Bad (The Float Test Is NOT The Safest)

Are those eggs in your fridge still safe to eat, or are you risking a case of food poisoning? It’s a common kitchen dilemma, especially as of December 18, 2025, when grocery prices and food waste concerns have everyone looking for ways to extend the shelf life of their staples.

The truth is, your eggs are often perfectly fine long after the printed "Best By" date, but relying on guesswork or old-fashioned methods can be a dangerous game. Knowing the definitive signs of a spoiled egg is the only way to ensure safety, and you might be surprised to learn that the popular egg float test isn't the most reliable indicator of actual spoilage.

The Definitive Egg Freshness Tests (Ranked by Reliability)

The U.S. Department of Agriculture (USDA) and food safety experts agree that while an egg's age can be determined by several methods, only one truly confirms if a raw egg has gone bad: the sniff test. Spoilage is caused by bacteria, and those bacteria produce tell-tale gases.

• The Unseen Story Jessica Simpsons Battle For Privacy And Body Image In A Digital Age Mlvqa

1. The Sniff Test (The Most Reliable Safety Check)

The sniff test is universally considered the most reliable method for determining if an egg is truly spoiled and unsafe to eat.

• The Method: Hold the egg up to your nose. If you detect any unusual odor, even before cracking it, discard it. If the shell smells normal, crack the egg into a clean bowl or plate and smell it again.
• What to Look For: A rotten egg will produce a distinct, unmistakable, and pungent sulfurous odor, often described as rotten cabbage or hydrogen sulfide gas.
• The Science: As spoilage bacteria multiply, they break down the egg's contents and release sulfur-containing gases. If the egg smells normal—meaning no odor at all—it's likely safe to use, regardless of the date on the carton.

2. The Cracked Egg Visual Test (The Ultimate Confirmation)

Once you've passed the sniff test, a visual inspection of the cracked egg provides the second layer of confirmation. This method checks for the physical breakdown of the egg's internal structure.

• Yolk and White Appearance: Fresh eggs have a high, round yolk and thick, slightly cloudy egg whites (also called the albumen) that clump tightly around the yolk.
• Signs of Spoilage: If the egg has gone bad, the yolk will be flatter, and the egg white will be noticeably thin and watery, spreading out across the plate.
• Color Warnings: Look for any discoloration. An iridescent look or a green/pink tint in the egg white is a strong indication of harmful bacteria, such as Pseudomonas, and the egg must be discarded immediately.

3. The Float Test (A Freshness Indicator, NOT a Safety Guarantee)

This is the most popular home method, but it's important to understand its limitations. The float test measures an egg's age, not necessarily its safety.

• The Chilling True Story 5 Key Facts About Richard Evonitz The Serial Killer Who Kidnapped Kara Robinson Chamberlain Xpjje

• The Method: Gently place the egg in a bowl of cold water deep enough to cover it.
• Fresh Egg Sinks: A very fresh egg will sink to the bottom and lie flat on its side. It has a tiny air cell and is dense.
• Older Egg Tilts: An egg that is a few weeks old will sink but stand on its pointed end, with the rounder end pointing up. This egg is older but still good for cooking, especially hard-boiling, as the larger air cell makes it easier to peel.
• Spoiled Egg Floats: An egg that floats is very old and should be discarded.
• The Science: As an egg ages, the shell is porous and allows moisture to evaporate and air to enter. This causes the internal air cell size to increase. When the air cell becomes large enough, the egg becomes buoyant and floats. However, an egg can float and still be safe to eat if it passes the sniff test, though it is usually best to discard it.

Understanding Egg Dates and Storage Safety

The dates printed on your egg carton are often misunderstood. Learning the difference between a "Sell By" date and when an egg actually spoils can save you money and reduce food waste.

Decoding the "Best By" Date on Your Carton

The "Best By," "Use By," or "Sell By" date is a measure of quality, not a hard-and-fast safety deadline.

• Sell By Date: This date is a guide for the retailer to ensure stock rotation. Eggs are typically safe to eat for three to five weeks after this date, provided they are properly stored.
• Actual Shelf Life: When kept consistently refrigerated, raw whole eggs in the shell can remain safe for consumption for up to four to five weeks beyond the pack date or about three weeks after purchase.
• The Key: Never rely solely on the date. Always use the sniff and visual tests if the date has passed.

The Critical Role of Proper Refrigeration

The single most important factor in preventing spoilage and the growth of harmful bacteria like Salmonella Enteritidis (SE) is proper storage.

• The Untouchable Privacy 7 Secrets Of Rachel Mcadams And Jamie Lindens Life Beyond The Red Carpet E820e

• Temperature is King: Eggs must be stored promptly in a clean refrigerator at a consistent temperature of 40°F (4°C) or below. Storing them in the carton, rather than the refrigerator door (where temperatures fluctuate), is recommended.
• The Bloom/Cuticle: In the U.S. and some other countries, eggs are washed, which removes the natural protective coating (the bloom or cuticle). This makes refrigeration mandatory to prevent bacteria from entering the porous shell.
• Cracked Shells: Never use an egg with a cracked shell, as the protective barrier is compromised, making it highly susceptible to bacterial contamination and spoilage.

Advanced Methods and Spoilage Entities

For those who want to be extra sure, especially when dealing with farm-fresh or older eggs, there are a couple of other checks you can perform.

Check the Shell and Listen Closely

Before you even crack the egg, you can check for external signs of trouble.

• Shell Inspection: Look for any signs of a slimy eggshell or a powdery residue. A slimy shell can indicate the presence of bacteria, while a powdery look could suggest mold.
• The Sound Test: Hold the egg up to your ear and shake it gently. A very fresh egg will be silent. If you hear a sloshing or shaking sound, it means the egg contents have thinned out significantly and the yolk is moving freely. This is a sign of an old egg, which should be used soon or discarded.

Egg Candling

Egg candling is a technique traditionally used to check the development of a fertile egg, but it is also a powerful tool for checking internal quality without cracking the shell.

• The Method: In a dark room, hold a bright light source (a strong flashlight works well) against the large end of the egg.
• What to Look For: The light illuminates the egg's interior. You can clearly see the size of the air cell. The larger the air cell, the older the egg. You can also look for dark spots or shadows that may indicate mold growth or other internal defects.

In summary, while the float test is a fun way to gauge an egg's age and help with peeling hard-boiled eggs, the most reliable and critical steps for safety are the sniff test and the cracked egg visual test. When in doubt—especially if you detect a rotten egg smell or see a discolored watery egg white—the safest bet is always to discard it to avoid any risk of foodborne illness.