Imagine this: You’re ready to whip up a delicious breakfast using eggs, only to find that the date on the carton has passed. Are those eggs still safe to crack open? Knowing How To Tell If Eggs Are Bad is essential for food safety and preventing unnecessary food waste. While “best by” dates are helpful guidelines, they don’t always indicate spoilage. Fortunately, there are several easy and reliable methods you can use to check egg freshness right in your kitchen.
1. Understanding the Sell-By Date for Eggs
According to the USDA, fresh eggs can be safely refrigerated for three to five weeks from the date of refrigeration. The “Sell By” date printed on the carton is primarily for inventory management for stores, not a definitive expiration date for consumers. Even if the sell-by date has passed, your eggs might still be perfectly fine to eat if stored properly at 40°F (4°C) or lower in your refrigerator. Keeping eggs consistently cold is key to maintaining their freshness and safety.
2. The Egg Float Test: A Quick Kitchen Experiment
The egg float test is a classic and effective method to assess egg freshness. Simply fill a bowl with cool water, enough to fully submerge an egg. Gently place the egg into the bowl. Observe what happens:
- Fresh Egg: If the egg sinks to the bottom and lies flat on its side, it’s very fresh.
- Still Good Egg: If the egg sinks but stands upright at the bottom, with one end slightly lifted, it’s still good to eat, but should be used soon as it’s not as fresh.
- Bad Egg: If the egg floats to the surface of the water, it’s a bad egg and should be discarded.
The science behind the float test is simple. Eggshells are porous, and over time, air enters the egg while moisture and carbon dioxide escape. This air accumulates in an air cell inside the egg. A fresh egg has a small air cell and will sink. As the egg ages, the air cell grows larger, making the egg more buoyant. A floating egg indicates a large air cell, meaning it’s old and likely spoiled.
3. Candling Eggs: Shining a Light on Freshness
Candling is a technique used commercially to check egg quality, and you can replicate it at home with a flashlight. In a dark room, hold an egg up to a bright light source, such as a flashlight or strong lamp. Shine the light against the large end of the egg. This illuminates the inside of the egg, allowing you to observe the air cell and yolk.
When candling eggs to check for freshness:
- Fresh Egg: Will have a small air cell, about 1/8 inch deep or less. The yolk should be centered and move slightly when you rotate the egg.
- Older Egg: Will have a larger air cell. The yolk may appear larger and move more freely.
- Spoiled Egg: May have a very large air cell, a detached yolk that is stuck to the shell, or dark spots inside.
While candling requires a bit of practice to interpret, it’s a useful method for visually inspecting the internal quality of an egg without cracking it open.
4. The Sniff Test: Trust Your Nose
The sniff test is perhaps the simplest and most direct way to tell if eggs are bad. Crack the egg into a clean bowl or dish and give it a sniff. Your nose is a powerful tool for detecting spoilage.
- Fresh Egg: Will have a neutral smell or a very faint eggy odor.
- Bad Egg: Will have a distinct, unpleasant, and often sulfurous or rotten smell. This smell is unmistakable and indicates that the egg is spoiled and unsafe to eat.
If you detect any foul or off-putting odor, discard the egg immediately, regardless of any other tests. It’s always better to be safe than sorry when it comes to potentially spoiled eggs.
5. The Egg White Examination: Look for Visual Clues
Finally, examine the egg white and yolk after cracking the egg into a bowl. The appearance of the egg white can provide further clues about freshness.
- Fresh Egg: Will have a thick, viscous egg white that sits up relatively high and a firm, rounded yolk.
- Older Egg: Will have a thinner, more watery egg white that spreads out more in the bowl. The yolk may also be flatter and break more easily.
- Spoiled Egg: Look for any discoloration in the egg white or yolk, such as pink, green, or black. These colors indicate bacterial contamination and the egg should be discarded.
While a watery egg white doesn’t necessarily mean the egg is bad, it does indicate that it’s older and the protein structure has started to break down. However, any unusual colors or foul odors are definite signs of spoilage.
When in Doubt, Throw it Out
Ultimately, if you have any doubt about the freshness or safety of an egg, it’s always best to err on the side of caution. Discard the questionable eggs and use fresh ones. These simple tests—checking the date, the float test, candling, sniffing, and examining the egg white—can give you confidence in determining egg freshness and help you enjoy your meals safely and without waste.
