At Simple & Homely, checking that the eggs we’re using are in-date isn’t very high on our priority list. Are we in the wrong for just cracking an egg, cooking it, and eating it?
In this article, we take a look at how to tell if an egg is out of date and what risks there are if you eat a rotten egg.
Ways to tell if an egg is out of date
The Best Before date
By law in the UK eggs have to be labelled with a Best Before date. This date is 28 days after the egg has been laid and can usually be found on the carton and stamped onto the egg itself, often styled like “BBJun30”, for example.
However, eggs are safe to eat beyond their best before dates, provided they are stored properly. The UK Food Standards Agency advises not to eat eggs more than a couple of days after their best before dates, regardless of your storage method.
To prevent the growth of bacteria in the egg, the FSA recommends storing your eggs in the fridge, rather than your cupboard, as the temperature is more consistent. Storing eggs in a place where the temperature is likely to change can lead to condensation on the shell. While you may have read that and pulled a face of disbelief, condensation on the shell can increase the rate of transfer of salmonella from the outside to the egg itself. And we all know salmonella is bad news.
The float test
While the egg float test is generally accepted as a way to tell if an egg is out of date, it may not be all it’s cracked up to be.
As an egg ages, the volume of air inside the shell increases. If an egg lays flat in water, then it’s said to be a fresh egg. If the narrow end points upwards, the egg is nearing the end of its life, and if it floats, then the egg has gone bad and should be binned.
However…
Notice, the volume of air changes as an egg ages. An egg two days after its best before date may stand upright in the water, but that doesn’t mean it isn’t safe to eat. As the UK FSA points out, the float test doesn’t tell you how much bacteria is in the egg. Just because your egg still isn’t floating five days after the best before date, it isn’t safe to eat as salmonella and other bacteria might’ve invaded. Stick to the Food Standards Agency’s advice of two days maximum beyond the best before date.
The sniff test
As we said above, as an egg ages the water in it is replaced by air – this isn’t fresh, countryside air, it’s the air that has seeped through the porous shell. This means if there’s salmonella on the shell, it can be transferred into the raw egg within. This isn’t the only source of the air you’ll find in a stale egg. As the egg rots and bacteria break down the proteins, gasses are produced.
We don’t need to tell you what a rotten egg smells like. When you crack it open, you’ll know if it’s stale. However, like the float test, you can’t rely on the sniff test alone. An old egg containing a harmful pathogen might not have a smell. Again, it’s safest to stick to the FSA’s best before advice: only use eggs up to two days past their best before dates.
Risks from eating out-of-date eggs
The real risk of eating an out-of-date egg is ingesting salmonella. The salmonella bacteria, when consumed, can lead to food poisoning. If you think you’ve eaten an out-of-date, keep an eye out for these symptoms:
- Diarrhea
- Stomach pain
- Fatigue
- Headache
- Nausea or vomiting
Salmonella doesn’t usually require hospital treatment, however you are advised to drink lots of fluids, replace lost electrolytes, and rest up. These symptoms can appear anywhere between six hours and three days after eating a contaminated egg, and can last for two to seven weeks. So, if you’ve eaten a rotten egg, prepare to spend a lot of time on the loo and just as much time washing your hands.
