How to tell if eggs are rotten

Question

Over the past couple of weeks our local supermarket has been selling eggs very cheaply. (large eggs for half the price of medium eggs). So we've been eating a lot of eggs, not a problem, but I still have a few dozen left and need the counter space. I am well aware of the drop them in water and see if they float technique - here and here. But I have been finding that a few have slipped through the net. My question is: Are there any other fool proof methods to telling if an egg has gone off or not?

Please note that the first link is a site that I own, it's just that I wrote an egg page a long time ago.

Answer 1

Besides the water bowl test I found these other tests from this site:

The cracked egg and plate test

Crack the egg in a flat plate or flat surface and check for the below signs:

The yolk of a very fresh egg will have a round and compact appearance and it will sit positioned quite high up in the middle of the egg. The white that surrounds it (albumen) will be thick and stays close to the yolk.

A cloudy colouring to the egg white is a sign of extra freshness, as this "cloudiness" is in fact carbon dioxide, which is present when the egg is laid. Over time, the egg white will become more transparent, as the carbon dioxide dissipates.

A less fresh egg will contain a flatter yolk that may break easily and a thinner white that spreads quite far over the plate.

In the last instance, a bad egg will have a very flat yolk and the egg white, or albumen, will be runny like water almost. If your egg is like this, it needs to be discarded and should not be consumed.

This characteristics can be noted if you don't rely on the smell.

The sound test

This method is not as widely used as the previous two, but it can work just as well, although you will have to rely on your hearing rather than your sight.

First, ensure there are no background noises which may affect this test, for example, if you have the washing machine or a dishwasher running in the kitchen then go to a different room.

Pick up the egg that you want to test and place it close to your ear.

Gently shake the egg from side to side. If you cannot hear any sound whatsoever, the egg is perfectly fine to eat and there is nothing wrong with it.

If, on the other hand, you hear a sloshing sound, do not consume the egg as it is bad.

If you are unsure after carrying out this test, you could try one of the first two tests just to make sure.

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You can do the sound test first and try to guess if it's good or bad, then use the water and bowl test and then crack it on a plate.

This way you will train your ear to identify a bad egg by sound after checking the result of the other two tests.

Answer 2

There are only two methods I found fool proof:

1. If in doubt, assume it gone bad.

2. Break the shell, open it, and see & smell. Pour content into a glass, not directly on the pan or whatever. That way, if it's good you can still add it, and if it's bad, your dish is not ruined.

I prefer method 1. if I can afford it. On the trail, or in a camp in woods, or when I was short on money, I used 2.