How to Tell If Eggs Are Bad: 3 Methods to Determine Freshness


An egg consists of a delicate and protective shell that contains the egg white and yolk. Eggs do rot, and consuming such eggs may be harmful to health. Just by looking at the egg, it is difficult to determine if it is good or bad. So how to check if eggs are bad?

Many people refer to the date on the packaging for that purpose. The “best before” date doesn’t always mean that the eggs are bad and should be thrown away. Eggs are safe to consume even if the packaged date tells us to discard them. Did you know that eggs can be tested for freshness even before they are cracked? Let’s take a look at how to tell if eggs are bad.

How to Check If Eggs Are Bad: The Freshness Test

To check the freshness of eggs, you can do three easy tests.

1. The egg float test

When immersed in a bowl of water, if eggs sink are they good or bad? Many people are confused about the egg float test results. They are unsure whether to use eggs that do not sink completely to the bottom, or those that tilt a bit.

For the test, you need to put the egg in a wide glass or bowl of cold water. The egg covering or shell is a bit porous. There is a tiny air pocket in the egg, and with time, more and more air enters inside through the porous shell. This makes the air pocket grow larger and the egg more buoyant. Fresh eggs have less air and so they sink to the bottom while old eggs float.

Float Test
If the egg floats, check the smell or the physical appearance to determine its freshness after you crack it open. A bad egg will smell foul and pungent as soon as you crack it open. It smells a lot like hydrogen sulfide. Also, there could be discoloration of the egg white.

The egg float test is more of a folklore and is only partly true. Just by checking if it floats or sinks, you cannot confirm if it is still edible. The smell test does give you a better idea once the egg is cracked open. But even if there’s no fowl smell, there is a chance that the egg may be contaminated with Salmonella.

Before cooking an egg, make sure it does not have any hairline cracks on the surface that can allow bacterial contamination. Some eggs could have feathers and poo stuck on them, which could very well contain bacteria. So avoid using dirty eggs even if they don’t smell bad. Also, avoid washing the egg to remove the dirt on it because it makes them all the more porous.

2. The sound test

Another test for egg freshness is the sound test, where you hold an egg near your ear and shake it. As time passes, the egg white and yolk begin to dry out and shrink, as moisture and carbon dioxide escape through the shell.

Also, the air pocket in the egg becomes bigger, allowing more space for the egg white to move around. If you hear a sloshing sound, the egg may have gone bad. If you don’t hear any sound, then it’s safe to eat.

3. The plate test

The next test to check if an egg has gone bad is to crack it open into a plate or a large bowl. A fresh egg will hold together and stay compact, while an old one will spread over a wide distance on the plate. An egg that seems watery has a thinner white, and so it spreads on the plate.

Observing the egg white and yolk will also indicate the freshness of the egg. If the yolk is flat and breaks easily, it is an old egg.

If the yolk moves around easily, the strands of egg white that hold the yolk in place have weakened and the egg is aging. A fresh egg has a cloudy egg white, while a clear white indicates that it is an old egg, but can still be consumed.

Packaged Date and Time

The date on the package also indicates the freshness of the eggs. It is generally referred to as the “expiry” date, “sell by” date, “use by” date, or “best before” date.

This date is around 30 days from the packaging date. The Egg Safety Council and FDA both advise that a reasonable use-by date is four to five weeks after the eggs were packaged.

Eggs can last for a month beyond the sell-by date if they are refrigerated and not broken. The sell-by date is the last day when the eggs should be available for purchase. After that, they are not meant to be sold, but that doesn’t indicate that the eggs can’t be consumed. You can test their freshness by using the tests mentioned above.

Identifying the Bad from the Good

1. Check if the egg smells

To identify a bad egg, you need to crack it open and check if it smells. A bad egg will emit a sulfuric smell as soon as it is cracked open. Such eggs should be immediately discarded. A bad egg will have a foul smell even after it is cooked.

2. Check the color of egg white

The color test holds true in case of raw eggs. You can check for the color of the egg white after breaking the egg into a plate. The color of the egg yolk depends on the hen’s diet, and the yellow or orange color isn’t related to freshness.

If the egg white appears green, pink or has some different color, it shouldn’t be consumed as it may be contaminated with Pseudomonas bacteria.

Black or green spots inside the egg indicate that it is contaminated by fungus and should be thrown away. If the yolk of a hard-boiled egg has a green ring around it, it means the egg was overcooked or was cooked in water that had a high iron content. The egg can be consumed safely.

A blood or meat spot on the egg doesn’t mean it is contaminated. It can still be consumed. The spot occurs if a blood vessel ruptures when the egg is forming.

Keep Your Eggs Fresh Longer

The way you store eggs will decide how long they stay fresh. Eggs should never be stored in the egg compartment of the refrigerator. The egg compartment inside the door is the worst place where you can keep the eggs.

Eggs should be kept in the main part of the fridge because it’s colder and has a stable temperature. It is best to store the eggs in their original container. This will prevent them from absorbing other flavors in the fridge and keep them fresh.

Eggs should not be washed until they are ready to eat. Eggs have a protective outside covering known as “bloom,” which protects the eggs from bacteria. How to check if eggs are bad isn’t a tough task. Just be sure to carry out these simple tests to enjoy all the benefits of this protein-rich food.



“How to Tell if an Egg is Bad,” wikiHow;, last accessed March 28, 2017.

“Myths and facts about eggs,” SA Heath;, last accessed March 29, 2017