Have you ever cracked open and egg whilst preparing a dish, only to find that the egg had gone bad and ruined the rest of your ingredients? Due to the nature of eggs shells making it impossible to visually check your eggs for freshness, it can be difficult to know whether the next egg you crack is fresh, or maybe should be put in the waste.

Thankfully there are some simple tricks to check whether an egg is fresh and steps you can take to minimise your eggs going bad sooner than needed.

How can you tell if an egg has gone off?                  

Eggs sold in Australia by law must have a best before date marked on the packaging so this should be your first step in determining whether your eggs should be OK. You should always store your eggs in the carton as this provides additional protection from the porous shell absorbing contaminants.

If you’ve taken the eggs out of the carton to store in your egg section, have mixed eggs or just otherwise can rely on the packaging for a reliable best before date there is a few options.

Option 1: Smell test

It may seem obvious, but eggs which have gone ‘off’ will have a distinct scent similar to sulphur which you can even smell faintly through the shell. If you can’t tell whether the egg smells and is bad, you can double check by cracking the egg into a small bowl and check the smell and colour. Eggs which are off will start to show more of a green hue and the smell should be distinct when cracked. Fresh eggs will have no smell at all and are safe to use.

Option 2: The float test

A reliable and safe method for checking your eggs freshness is via the float test. To complete this test fill a container with cold water and place the eggs you’re checking in the water. Fresh eggs will sink and remain on the bottom lying flat on their side, while bad eggs which have gone off will either float or sit on the bottom pointing upwards – this is because as an egg goes bad air will begin to build up in the shell making it buoyant. If the egg is floating or pointing upwards (due to it starting to go bad), throw it out.

What does an egg which has gone off look like?

You generally can’t tell if an egg has gone bad just from looking at the shell unless it has significantly gone off and has discoloured or leaking through cracks. To get a good look at an egg which has gone bad, you need to crack it open. Using either a small bowl or a plate, crack open the egg so both the yoke and egg white can be easily inspected. A fresh egg will have a consistent yellow yoke and thick clear egg which holds its form easily. If the egg has gone off, the yoke will start to lose its round form and both the yoke and egg white will start to go runny. Eggs which have been off for a significant period of time will start to heavily discolour with a green brown tinge. The smell will be considerable at this time, hence the well-known phrase of something smelling of ‘rotten eggs’.

How can I protect my eggs from going bad?

No matter how well you treat your eggs, they will always go off with time however there are some things you can do to keep your eggs staying fresh for their maximum time possible and avoid prematurely making your eggs go bad. The three factors which will impact an eggs freshness are temperature, moisture and cracks in the shell.


In Australia you can purchase eggs which are refrigerated or room temperature at purchase. You can store your eggs in either format, but the best option is to refrigerate to maintain freshness and avoid your eggs experiencing significant temperature swings. Consistent temperatures are incredibly important because if your eggs go from cold temperatures to room temperature for significant periods of time can lead to condensation on the shell which can be absorbed and bring bacteria into the egg.


As above, moisture allows for a vector where bacteria can penetrate the shell and cause your eggs to prematurely go bad. Avoid leaving eggs which have been in the refrigerator out for more than an hour if they will not be consumed immediately. Likewise do not wash your eggs when you purchase them, as they would have already been cleaned and submerging them in water can actually lead to the eggs being more exposed to bacteria than if you left them. Keep your eggs in their original cartoons too, as the cardboard used in cartons will generally absorb any ambient moisture before it reaches the egg.

Cracks in Eggs:

Inspect your eggs when purchasing looking for any cracks or soft shells. A handy tip is to try move each egg in its carton as a cracked egg will usually stick to the carton and you will be unable to ‘jiggle’ the egg. Avoiding these eggs means that the shell will be in a complete unbroken form reducing the potential for disease to enter the vulnerable liquid internal section of the egg.  

Follow the used by date for your eggs, but if you’ve received eggs from someone who has chickens or raise your own, a general rule of thumb is that eggs will retain their freshness for 6 weeks from being laid. Ensure you rotate through your eggs using the oldest eggs first and if you have a considerable amount of eggs, keep the dates they were laid to ensure you don’t risk using an egg which has gone off.

What happens if you eat an egg that has gone off?

If you consume an egg which has gone off, you put yourself at risk of being exposed to bacteria which can lead to food poisoning from E. coli or more commonly Salmonella. If you do get exposed to this the common symptoms which include:

  • Abdominal Cramps
  • Vomiting
  • Diarrhoea
  • Fevers
  • Loss of appetite

If you are exposed symptoms will develop quickly, generally the same day within the first 6 hours and at latest within 2 days. Outside of the uncomfortable symptoms food poisoning will go away without treatment, but you should check with a doctor to receive the best advice on how to treat your situation.

How long do boiled eggs last in fridge?

Hardboiled eggs are different to their fresh counterparts due to the cooking process stripping the membrane protection that fresh eggs have. Without this protective coating hardboiled eggs are more exposed to bacteria which can make them go bad. Due to this, hardboiled eggs can only last up to 7 days refrigerated after being cooked, or 4 days if already peeled. It is essential to refrigerate your eggs once cooked, otherwise as they lower to room temperature they will be exposed to rapidly increasing amounts of harmful bacteria.

I hope this helps you better understand how long eggs take to go off and what you can do to check the freshness of your eggs. Do you have any handy tips on checking eggs? Let us know.


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