Egg Float Test and Other Methods of Checking Egg Freshness

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Last Updated on October 10, 2024 by Alice Benny

Using the egg float test is a way to find out if your eggs are fresh and safe to eat. You likely won’t be buying “farm fresh” eggs from the supermarket. Using this test will help determine if the eggs are expired.

In most cases, the eggs you purchase will probably be a couple of months old. This is because farmers are usually given 30 days to pack eggs, and stores have the same amount of time to sell packaged eggs.

The problem is relying on the packaging to tell you if your eggs have expired might mean tossing aside a batch of perfectly usable eggs.

Fortunately, you can use the egg float test if an egg is bad. We’ll teach you how to check if eggs are good and what it means when eggs float.

We’ll explain the science behind it along with the myths. In addition, you will learn other ways to check if eggs are fresh or if the eggs are expired. In addition, you will learn how to store eggs correctly. 

Egg Float Test 

Also known as the egg sink and float test, this is a simple method claimed to be effective in checking if an egg is fresh or old. Generations of families have used the egg float test to see if an egg is expired. You just need a glass of water.

How Do You Perform the Egg Float Test

The floating eggs test takes just five minutes to check an entire carton of eggs.

Step #1: Fill a Bowl With Cold Water

Begin by filling a bowl or container with enough cold water so that it will submerge an egg completely.

Estimate correctly, making sure there will be two inches of space left between the topmost portion of the egg and the water’s surface.

Step #2: Place Eggs Into the Water

Place eggs in bowl of water one at a time. Make sure the eggs you’ll test are uncracked. Cracked eggs are best tossed away or fed back to hens.

Step #3: Examine the Results

When you dip the egg into water, three things can happen.

If egg floats:

If the egg floats, this means you may have a bad egg that needs to be tossed out.

Egg is upright:

If the egg takes an upright position but is still below the water’s surface, it is no longer as fresh but is still good enough to consume.

If the egg lies on the bottom:

The egg is fresh if it lies on its side at the bottom.

How long do fresh eggs last

Can an Egg Still Be Consumed If It Fails the Test?

Whether an egg floats completely or remains upright beneath the water’s surface, it is considered a “failed” egg test. As far as consumability is concerned, though, these two results entail two different things; hence, the egg float test myth opinion of other people.

A floating egg means you shouldn’t eat it.

An egg that remains upright under water means you can still use it in recipes or cooked as is. An “upright” egg may not be the freshest scrambled or sunny-side-up egg, but it won’t make you sick or cause you harm. Many people hard boil them to ensure they are fully cooked before eating. 

Conversely, an egg that floats on the water’s surface will almost always taste unpleasant.

Although it’s not necessarily unsafe to eat, it is riskier to consume because of the larger window of time microbes have had to penetrate its shell and mix into its contents. That is why people often choose to toss out eggs that have been unused for so long.

Other factors to consider

In and of itself, the float test won’t tell you if an egg is safe for consumption.

First, check the egg carton. Be sure to buy cartons that are clean without signs of egg yolk, cracked eggs, or dirty eggshells. Use your eyes and nose to detect anything off-putting.

You also need to look into how the egg was handled, specifically, if their nesting boxes were clean and if eggs were collected promptly and stored correctly.

Aside from these instances involving the egg test that can help tell if an egg is still consumable, you can crack it into a separate bowl.

This way, you don’t ruin and throw a perfectly consumable batch when it does turn out not to be contaminated.

It is especially convenient if you plan to cook a scrambled egg, sunny-side up, or any other egg meal that doesn’t require the shell. Fresh eggs will have a bright yellow or orange yolk.

As for the results, if an egg is spoiled, once it’s cracked into a container, it will look unusual and give off an unpleasant odor.

Some rotten eggs, both uncooked and cooked, can smell like sulfur and contain a spotty white or yolk that could lead to an upset stomach when consumed.

Will the Results of the Test Be Influenced by the Way the Eggs Were Stored?

While the temperature of the eggs’ storage area won’t directly impact the results of the test, it will influence how long the egg will stay usable.

Storing a batch of eggs at room temperature will usually make the eggs last about a month and two weeks.

Keeping them in a fridge could easily double this period of usability to 90 days or three months.

Does Egg Float Test Work?

Determining whether the test works or not will depend on what you’re actually trying to test.

Checking if Egg is Safe to Consume

The fact that the old-fashioned floating eggs test is still relevant today tells you that its results are fairly accurate. We say “fairly” because it does not necessarily reveal if the egg is spoiled or contaminated.

To figure this out with 100% accuracy, you still have to crack the egg open and see how its insides look and smell.

Determining Egg’s Age

Those who frequently rely on this method can become experts at determining an egg’s age based on how it’s positioned in the water.

What makes this process reliable has to do with how eggshells are structured.

The shell of an average egg houses thousands of minuscule pores through which moisture, air, and microorganisms can pass through.

Before hatching its eggs, the hen coats their shells with a layer of film called the bloom or cuticle, which covers the pores and defends the eggs’ contents from spoilage-causing bacteria.

Fixed between the egg white and shell are two membranes that serve as additional protective layers against microbes.

These membranes bond closely to the shell right before an egg is laid, but pull away from it as soon as it is laid.

This then results in an air space forming between the layers. This space will then function as a reservoir for oxygen for a chick before it hatches.

As time passes from when an egg is laid, the layer of protective film coating its shell recedes, widening the pores and allowing more air to enter.

At the same time, its oxygen reservoir also expands, providing more space for air to settle.

Both these events eventually lead to the egg absorbing more air and becoming more buoyant, reinforcing the reliability behind the mechanics of the float test in estimating an egg’s age.

When Eggs Float What Does That Mean?

If eggs float when conducting an egg test, it tells you that the pores covering the eggshell are wide enough, giving it a buoyancy level that can only be achieved when an egg is old or “no longer fresh”.

In fresh eggs, the pores are tinier, so there’s little to no buoyancy, resulting in an egg that sinks to the bottom.

How Do You Test If an Egg Is Bad or Fresh: Other Methods to Consider

If you’re not too comfortable with or confident of the floating test for eggs, there are other traditional techniques for testing an egg’s freshness.

Checking Whole Eggs

If you need to check the quality of the eggs that you’re about to sell, share, or buy, you can choose from the following tests:

1. Carton

The carton test is a method you use on store-bought eggs. For this method, you need to note some information on the egg’s carton, namely the packing plant number, the day of the year packing took place, and the “Best By” date, which indicates the date when you need to remove the eggs from the shelf. Think of this as checking the expiration date for eggs.

2. Candling

The candling technique specifically tests for egg quality before selling. While it could also determine an egg’s freshness, it’s no longer as reliable when the egg tested is older.

For the candling method, place the candle next to that egg’s large end to illuminate it. If you have an old or bad egg, the content doesn’t fill the shell completely.

3. Flashlight

You can also use the flashlight test instead of the floating test for eggs.

It involves lighting up the egg’s insides using a flashlight, or historically, placing a cardboard piece in front of a light source and positioning the egg in front of it.

Using whichever version of this method, you will be able to see the airspace and detect the presence of mold in the egg.

4. Shaking

This method requires you to shake the egg and listen for the sloshing sounds, which signifies that the egg is no longer fresh. Otherwise, if you hear nothing, the egg is still okay for eating.

That said, many people doubt this method’s accuracy, so it’s best to avoid it.

egg float test
Use the egg float test to learn if eggs are fresh or old.

Testing Cracked Eggs

If you don’t require the eggshell intact because you’re about to cook the egg or use it in your recipe, there are several ways to check if it is still good.

1. Plate Test

The plate method is one of the simplest techniques. You need to crack the egg onto a plate to test its freshness.

If you see an orange or bright yellow yolk with a not-too-spread-out egg white, you have a fresh egg.

2. Sniff Test

If what comes out of the egg shell doesn’t quite fit the description of a fresh or bad egg, give it a good sniff.

More often than not, you’ll immediately notice if an egg is bad once you’ve cracked it since it has a rancid smell. Fresh eggs should be relatively odorless.

3. Egg White and Yolk Consistency

When eggs are older, their yolks will be flatter, and their whites runnier. They’re not necessarily bad, especially when you’re after a good hard-boiled egg.

Which Methods for Testing Egg Freshness Are the Best?

While there are several ways to test for the freshness of uncracked eggs, the one that gives the most accurate results is the floating egg test.

As the above directions for doing the test indicate, you simply have to submerge the uncracked egg in cold water and see how it reacts.

As for determining how fresh cracked eggs are, the combination of the plate and sniff methods is arguably the best.

Just crack open that egg on a plate and see how it looks (and smells!). If the yoke appears in a gorgeous bright yellow or orange color with a mostly-intact egg white, it’s as fresh as an egg can get.

If it immediately gives off a putrid smell, it’s time to toss that egg.

How to Store Eggs Correctly

Determining freshness isn’t enough to ensure the eggs stay fresh and safe to consume. You need to store the eggs properly to maintain their quality or prolong their lifespan.

Back then, you could probably get away with just placing eggs on the kitchen counter, ready for use, without any issues. These days, such a method may no longer apply because of different factors.

Using past storing practices, you could easily encounter problems associated with contamination, cleanliness, and disease. Eggs can’t sit out for hours in many cases, especially after they’ve been cooked.

This day and age may have given us more affordable foods, but questionable farming methods made our grandparents’ egg-storing practices no longer a good choice.

If you eat a contaminated egg, the Centers for Disease Control and Prevention (CDC) say symptoms typically develop within 6 – 48 hours.

How to Store Eggs Correctly
Store eggs correctly so they will be fresh and safe to eat.

That said, here are the best ways to store your eggs so that they last for quite some time:

1. Refrigeration

With the refrigerator, there’s no need to hold on to a tradition that has been deemed unsafe or unhealthy. Instead, you can create a new tradition of safe egg storage.

You’ll want to store your eggs in a refrigerator with a temperature ranging from 40 to 45 degrees Fahrenheit.

Avoid storing eggs in your fridge’s door since the fluctuating temperature from the opening and closing of this part can mess with their quality.

Instead, place them in a carton and store them in the coolest section of your refrigerator.

If you refrigerate them at the right temperature, eggs should have no problem lasting for eight weeks. Of course, they may no longer be fresh at that time, but they are still safe to consume.

2. Freezing

It’s important to know how to store foods long term. If you want your eggs to last even longer than refrigerated ones, the best solution is to freeze them.

To start, you need to break and beat them slightly. Then, grab a large ice cube tray and fill each cube with some beaten eggs.

You may also separate the yolks from the whites, especially if you love cooking recipes requiring any of the two.

This method should help keep your eggs for up to 12 months. Take note that freezing eggs will reduce their freshness, which means it is best to use them for baking or an ingredient of any recipe.

Also, to make sure the eggs are free from eggshells or to separate the yolk and the white cleanly, you must crack the eggshell properly.

FAQs About Egg Quality

1. What are the spots inside eggs?

Black spots are indicative of a mold infestation. If your egg has either black or green spots, make sure to toss it out immediately.

Brown or red spots, on the other hand, while off-putting, are perfectly safe to eat.

2. What should I do if my egg has a blood spot?

While a blood spot can discourage you from eating an egg, it won’t harm or affect the egg’s taste.

That is the result of a blood vessel breaking during the ovulation process.

In rare cases, the blood can come in a pinkish shade. If the presence of too much pink in the blood is causing you to doubt the quality of the egg, toss it out.

3. Is it safe to eat a pink yoke?

The whites on your eggs should be either clear or cloudy and not have any coloring.

If the albumin has any pink coloring on it, it could be indicative of contamination, so it isn’t safe to consume.

4. Do egg labels make a difference?

Some labels do matter because they tell you how the hens that produced the egg were treated.

Cage-free, for instance, means that the hens were free to roam in barns or large chicken houses instead of being confined in small spaces.

If the label indicates “USDA Organic”, that tells you the eggs come from uncaged hens provided with GMO-free, organic, and vegetarian feed.

As for labels that are okay to ignore, there’s “natural”, which means nothing was added to the egg; a fact that is true for all eggs.

Next, there is the non-relevant “Produced Without Antibiotics” label, which doesn’t matter because hens aren’t being given antibiotics in the USA.

Of course, if you are very particular with the nutrients you get from eggs, the “Omega-3” label should definitely matter. This label means that hens fed with a consistent fatty-acid-rich diet produced the eggs.

5. Does boiling an egg kill salmonella?

Cooking until no visible liquid remains is a way to kill bacteria in eggs. When the whites are completely set and the egg reaches a temperature of 160 degrees F. Boiling until the eggs aren’t runny is essential.  

The Egg Sink or Float Test

Use the egg float test to reveal if an egg is spoiled or bad. It works well when you use it with other factors such as looking for signs of spoilage, smells, etc.

The egg sink or float test is among the most accurate ways to test for an egg’s freshness. That is because it relies on eggshell porosity and certain anatomical functions of the egg that directly influence its buoyancy, reflecting its age.

We may not need to use it all the time, but it will serve a purpose once in a while. You’ll find this method especially useful if you buy eggs from the supermarket. Choose cardboard cartons and use leftover egg cartons for compost.

Learn about turkey eggs and duck eggs vs chicken eggs. For health and safety, it’s important to know how to tell if an egg has gone bad. After all, you could be purchasing eggs as old as two months, which means you definitely have to be aware of how fresh or “not fresh” they are.