Tests such as a float test or a sniff test can help you determine if your egg is good or bad.

Almost everyone has been faced with this conundrum — you reach into the fridge for an egg, but can’t remember how long they have been sitting there.

It’s true that over time, an egg’s quality begins to decline as the air pocket inside gets larger and the whites get thinner. However, an egg only “goes bad” when it starts to decompose because of bacteria or mold.

When in doubt, there are several methods you can use to determine if eggs are safe to eat. Here are the top 4 tips to tell if your eggs are good or bad.

Check the expiration date

One of the easiest ways to tell if your eggs are still good is to check the date on the carton. But if you throw your refrigerated eggs out as soon as this date arrives, you could be wasting perfectly good eggs.

In the United States, eggs may be labeled with either a “sell by” or expiration date, depending on which state you live in, to let you know if your eggs are still fresh.

Sell by date

A “sell by” date indicates how long a store should offer eggs for sale — no more than 30 days after packing — but not necessarily that the eggs have gone bad.

Expiration date

An expiration date, on the other hand, marks the date after which the eggs are considered less than fresh.

If neither of these labels is present, there is yet another date you can look for to tell how fresh your eggs are.

Pack date

Eggs that the USDA has graded are required to show the “pack date” on the carton, which is the day that the eggs were graded, washed, and packaged. But you may not recognize it if you don’t know what to look for.

What it means

If your eggs are still within the expiration or “sell by” date on the carton or within 21–30 days after the “pack date,” you can be pretty sure they are still fresh.

And even though the quality of an egg may start to decline after a certain date, it may still be good to eat for several weeks, especially if it has been refrigerated, which preserves the quality and prevents bacterial growth.

However, if your eggs are past the date printed on the carton, you may need to use another method to tell if the egg is good or bad.

Conduct a sniff test

The sniff test is the oldest, simplest, and most reliable method of telling whether an egg has gone bad.

If you find that your eggs are past their “sell by” or expiration date, you can tell if they are still good with a simple sniff.

Eggs that have gone bad will give off an unmistakable smell, regardless of whether they are raw or cooked.

If you can’t already tell while the egg is in the shell, crack the egg onto a clean plate or bowl and give it a sniff. If anything smells off, toss the egg and wash the bowl or plate with hot, soapy water before using again.

If things smell normal, meaning there is no odor at all, that’s a good sign that the egg is still safe to use.

Complete a visual inspection

In addition to your nose, your eyes are a valuable tool for telling whether an egg is good or bad. While the egg is still in its shell, check that the shell is not cracked, slimy, or powdery.

Sliminess or cracks can indicate the presence of bacteria, while a powdery appearance on the shell may indicate mold.

If the shell appears dry and undamaged, crack the egg into a clean, white bowl or plate before using. Look for any pink or iridescent discoloration in the yolk or whites, as this may indicate bacterial growth.

If you notice any signs of discoloration, throw the egg out and wash the bowl with hot, soapy water before testing a new egg.

You can also check to see if the whites or yolk of the egg are runny. This is an indication that the egg is old and that the quality has declined.

Perform a float test

The float test is one of the most popular methods for checking whether an egg is good or bad. This is also a common methodTrusted Source for determining the age of a fertilized egg that is developing into a chick.

To perform the float test, gently set your egg into a bowl or bucket of water. If the egg sinks, it is fresh. If it tilts upwards or even floats, it is old.

This is because as an egg ages, the small air pocket inside it grows larger as water is released and replaced by air. If the air pocket becomes large enough, the egg may float.

While this method may tell you whether an egg is fresh or old, it doesn’t tell whether it is good or bad. An egg can sink and still be bad, while an egg that floats may still be fine to eat.

The bottom line

A lack of knowledge about telling when an egg has gone bad makes some people throw away good eggs needlessly.

Among the strategies listed here, cracking an egg open, sniffing it, and checking for discoloration is the most conclusive method of determining freshness.

Remember that eggs containing bacteria that cause food-borne illness, such as Salmonella, may look and smell completely normal.

So don’t forget that even if an egg passes these tests, it’s important to fully cook it to a safe temperature before you eat it.