How To Tell If Eggs Are Off

How many times have you cracked an egg into a bowl of other ingredients, only to question whether the egg has gone bad or not? Unfortunately, eggs are not the easiest ingredient to determine the freshness of as the protective opaque shell hides the condition of the white and yolk.

But there are six easy ways to tell if an egg is fresh, along with plenty of simple measures you can take to prevent your eggs from going bad in the first place.

How to Tell If Eggs Are Off in 6 Ways

1. Check the Carton Date & Julian Date

All egg cartons and trays sold in Australia must be marked with a best before date and this is the easiest and most reliable way to check whether eggs are still ok to eat.

You may also notice a Julian date – a three-digit code showing the exact day the eggs were packaged (e.g. 5 January’s Julian date is 5, whereas 24 December is 358 ).

The best before date signifies the end of the period in which eggs are safe to eat and is calculated as six weeks from the day the egg is packed into the carton, i.e. the Julian date.

Comparing both of these dates can help you decide whether your eggs have gone off.

2. Sniff Test

But what if you’ve stored your eggs without the carton? Well, in short, you should always store eggs inside the carton you bought them in, inside the fridge. Egg shells are porous, and the carton helps protect the eggs from any potential contamination.

If you don’t have the best before date, it’s sometimes possible to determine a bad egg simply by smelling it. Good eggs don’t smell at all but off eggs will emit a slight sulfuric smell that warns you something isn’t right.

If you’re unsure, crack the egg onto a clean plate to smell it properly. If there’s any pungency, throw away the egg and wash the plate thoroughly.

3. Egg Freshness Float Test

A cleaner and undoubtedly more fun method is to conduct the egg floating test. This is not a myth; fresh eggs sink while bad eggs float to the top.

Simply fill a bowl with cold tap water and place your eggs in it. If they sink to the bottom and lie flat on one side, they are fresh and good to eat.

Older eggs tilt or stand upright due to the expanding air sac. While they might not be ideal for your morning scramble, they’re great for boiling (the air cell makes them easier to peel).

On the other hand, rotten eggs float entirely because of a larger air bubble inside. Any floating eggs should be thrown out.

4. Shake Test

Give the egg a gentle shake near your ear.

Hear a watery slosh? Time to wave goodbye to an old egg. Egg whites break down as the egg ages. Frequent temperature fluctuations can speed up this process, which is why it’s so important to store your eggs in the carton in the fridge (not the door). The fridge door is exposed to constant changes in temperature every time it opens.

5. Egg Candling Trick

Have your phone torch handy? You might be able to tell if your eggs are off without cracking open the shell.

First, dim the lights in your kitchen. Then shine a bright light (candling) through your egg to spot hidden flaws.

• Fresh eggs appear opaque with clearly defined features (e.g. air cell at the wider end, visible yolk shape, etc.)
• Older eggs will show a larger air cell and have less distinct features.
• Bad eggs tell a different story entirely and will appear murky, with undefined yolk and albumen.

6. Visual Inspection

When all else fails, give that shell a crack and see for yourself. Once the yolk is out of its shell, you’ll be able to see clearly whether or not your egg is off. Fresh eggs feature bright, rounded yolks and thick whites. Older eggs will have flat, discoloured yolks and runny whites.

What About Storing Hard-Boiled Eggs?

It’s a different story when it comes to hard-boiled eggs as they have a far shorter shelf life than raw shell eggs. This is because the process of boiling an egg removes the protective outer coating of the shell, which makes it more porous and more vulnerable to bacteria and other contaminants.

Hard-boiled eggs can last for up to one week in the refrigerator if they remain in the shell or about five days if peeled. Just make sure you refrigerate the eggs within two hours of cooking.

What Does a Bad Egg Look Like?

It’s hard to tell if an egg is off just by looking at the shell. It could have cracks or discolouration on it but generally, an egg needs to be cracked to determine its freshness.

To check the state of an egg, crack it onto a plate and look carefully at the colour and thickness of the white and yolk. A fresh egg should have a bright yellow or orange yolk and a thickish white that doesn’t spread too far. If it’s off, the yolk will be flatter and discoloured and the egg white will be far runnier.

As we’ve already described, rotten eggs will also have a sulfuric smell to them.

How to Prevent Eggs from Going Bad

There are plenty of things you can do to keep your eggs fresh as long as possible. Below are just a few of the best methods to make sure you don’t end up consuming a bad egg:

• Check the eggs inside the carton before buying them and avoid eggs that have cracks or dirt.

• Get the eggs home as quickly as possible and don’t leave them in a hot car.

• Refrigerate your eggs in the carton they come in to prevent breakages, odour absorption, and water loss.

• Keep eggs in the coldest part of the fridge - usually a middle or lower shelf - rather than in the door where the temperature fluctuates more.

• Don’t leave refrigerated eggs out at room temperature for more than two hours. The eggs will sweat and that creates an environment conducive to bacterial growth.

• Keep refrigerated eggs for up to six weeks but always follow the best before date on the carton.

For more information, check out this article on how to safely handle and store eggs.

What Happens If You Eat a Bad Egg?

If you eat a bad egg, you are at higher risk of exposure to bacteria that can cause food poisoning, such as Salmonella and E. coli. Food poisoning symptoms may include:

• Diarrhoea

• Abdominal cramps

• Fever

• Vomiting

Symptoms will typically develop between six and 48 hours after eating a contaminated egg and can last between four and seven days. In most cases, the symptoms go away on their own.

Learn More About Cooking with Eggs

Australian Eggs is dedicated to bringing you valuable resources to help you get the most out of your eggs. Learn more important facts and tips about cooking with eggs at home, including egg handling and storage information.