How do you know when a refrigerated egg has gone bad?

[dnooman]

Egg packaging says that eggs can go bad in the fridge. How do I know when an egg that is not in it’s original packaging has gone bad?

Eggs are cheap enough to replace, but I’d hate to just waste money by buying “fresh” ones without good reason.

[picunurse]

Eggs stay for a long time refrigerated, but not forever. A way to tell if an egg is bad without opening it, is to spin it. The yoke in a good egg is “sloshy” so when you try to spin it, it won’t. It might make one slow, lazy turn, but not spin. A rotten (or boiled) egg will spin, because it has consolidated. If you crack an egg gently and the yoke breaks, its bad or or the edge of bad. If it has an unpleasant smell, like sulfer its really bad.

[Meeko]

I heard once, but cant find on the net again:

Good eggs sink to the bottom of a glass of water.

If an egg floats to the top, throw it out.

[Blake]

@picunurse

If you crack an egg gently and the yoke breaks, its bad or or the edge of bad.

Most likely the carton has simply been shaken on the way home from the shop, rupturing the yolk. That is by far the most common cause of broken yolks, nothing to do with being bad or old.

[TellMeI_mNotCrazy]

@Meeko

I heard once, but cant find on the net again:

Good eggs sink to the bottom of a glass of water.

If an egg floats to the top, throw it out.

Correct: a fresh egg will sink; the older the egg gets, the more it will float, due to the matter inside drying up, leaving a larger air bubble. However, the American Egg Board has this to say:

http://www.aeb.org/LearnMore/OtherQuestions.htm

The faster you use your eggs, the less time any potential bacteria will have to multiply. However, when properly handled and stored, eggs rarely spoil. Instead, as an egg ages, the white becomes thinner, the yolk becomes flatter and the yolk membrane weakens. Although these changes may affect appearance, they don’t indicate spoilage and don’t have any great effect on the nutritional quality of the egg or its functions in recipes. Rather than spoiling, if you keep eggs long enough, they’re more likely to simply dry up – especially if they’re stored in a moisture-robbing, frost-free refrigerator.

But, like all natural organic matter, eggs can eventually spoil through the action of spoilage organisms. Although they’re unpleasant, spoilage organisms don’t cause foodborne illness. The bacteria Streptococcus, Staphylococcus, Micrococcus and Bacillus may be found on egg shell surfaces because all these species can tolerate dry conditions. As the egg ages, though, these bacteria decline and are replaced by spoilage bacteria, such as coliform and Flavobacterium, but the most common are several types of Pseudomonas. Pseudomonas can grow at temperatures just above refrigeration and below room temperatures and, if they’re present in large numbers, may give eggs a sour or fruity odor and a blue-green coloring.

Although it is more likely for bacteria to cause spoilage during storage, mold growth can occur under very humid storage conditions or if eggs are washed in dirty water. Molds such as Penicillum, Alternaria and Rhizopus may be visible as spots on the shell and can penetrate the shell to reach the egg.

Discard any eggs with shells – or, for hard-cooked eggs, egg white surfaces – that don’t look or feel clean, normally colored and dry. A slimy feel can indicate bacterial growth and, regardless of color, powdery spots that come off on your hand may indicate mold.

[Manduck]

If the egg is smoking, hanging out on street corners, and being disrespectful to its elders, that egg has gone bad and is no longer suitable for omelets.

[picunurse]

@Blake

Most likely the carton has simply been shaken on the way home from the shop, rupturing the yolk. That is by far the most common cause of broken yolks, nothing to do with being bad or old.

Nope. You can shake an egg as hard as you can without breaking the yoke in the shell. The shape protects the yoke as it protects the embryo.
If you put your ultrasonic toothbrush against the shell, its a different story. (it doesn’t always work)

[Blake]

@picunurse

Nope. You can shake an egg as hard as you can without breaking the yoke in the shell. The shape protects the yoke as it protects the embryo.

I’m not sure where you got those ideas, but they sure aren’t true. You certainly can break the yolk by lightly vibrating the egg, such as occurs in a vehicle. In fact that is the single most common problem with egg quality today.

And the shape of the egg certainly doesn’t protect the embryo. If you were right that “you can shake an egg as hard as you can without breaking the yoke” because the shell protects the embryo then bird control would be very difficult. After all control of problem wild birds commonly involves involves shaking the egg and putting them back on the nest.

The shape of the egg provides no protection at all from addling. The shape of the egg provides protection from compressive forces, ie it stops the shell from cracking. However being irregular it probably makes the damage from shaking worse. What does protect the egg somewhat is the air pocket. However even that is of limited value. The fact is that eggs were designed to be laid in one spot and never moved. They were never designed to be carted around and moved vigorously. As such there simply was never any needto evolve a defence against shaking.

But hey, if you wnat to provide a reference that says that you can shake an egg as hard as you like without addling it and harming the embryo then by all means go ahead.

[Harmonious_Discord]

Throw them out if the albumin runs like water. They’re months old at that point. Hmm. Did I put the new ones on the right or left side?

[Ms2001]

I had eggs the other day that were two weeks past the date, and they tasted fine. How long do eggs usually stay good in the fridge?

[TellMeI_mNotCrazy]

@Mr2001

I had eggs the other day that were two weeks past the date, and they tasted fine. How long do eggs usually stay good in the fridge?

Well according to the American Egg Board, they pretty much stay edible until they dry up, barring bacterial invasions (I would guess the most common culprit of that would be an unsanitary refrigerator where there are science experiments growing). It’s been my experience that an egg that smells normal is fine to eat, although I’ve never had eggs really stick around longer than a month after I buy them. It was a big adjustment for me finding eggs on the shelf instead of the refrigerated section here, though, let me tell you.

[antechinus]

I have always thought that eggs which float should be thrown out. From what I read here it seems I have been misinformed.

Is this just an elderly-female-spouses-anecdote?

[iamthewalrus_3]

I have used 2 month old eggs before with no ill effects. They didn’t smell bad or look bad, but the yolks didn’t stand up as much when I fried them. Eggs will stay good for a week or two without even being refrigerated. It wouldn’t surprise me if well stored eggs could last for six months or more.

[danceswithcats]

Perhaps I’m misremembering, but recall a comment from a program which featured a family on a long sea voyage where the eggs were turned over weekly to preclude their going bad. Fact or fallacy?

[picunurse]

@Blake

I’m not sure where you got those ideas, but they sure aren’t true. You certainly can break the yolk by lightly vibrating the egg, such as occurs in a vehicle. In fact that is the single most common problem with egg quality today.

And the shape of the egg certainly doesn’t protect the embryo. If you were right that “you can shake an egg as hard as you can without breaking the yoke” because the shell protects the embryo then bird control would be very difficult. After all control of problem wild birds commonly involves involves shaking the egg and putting them back on the nest.

The shape of the egg provides no protection at all from addling. The shape of the egg provides protection from compressive forces, ie it stops the shell from cracking. However being irregular it probably makes the damage from shaking worse. What does protect the egg somewhat is the air pocket. However even that is of limited value. The fact is that eggs were designed to be laid in one spot and never moved. They were never designed to be carted around and moved vigorously. As such there simply was never any needto evolve a defence against shaking.

But hey, if you wnat to provide a reference that says that you can shake an egg as hard as you like without addling it and harming the embryo then by all means go ahead.

I wrote to the Canadian egg councel. They wrote back today. They said that when eggs are old, the yoke may break when shaken, so I owe you an apology. You are correct.

[Backwater_Under_Duck]

@danceswithcats

Perhaps I’m misremembering, but recall a comment from a program which featured a family on a long sea voyage where the eggs were turned over weekly to preclude their going bad. Fact or fallacy?

I don’t know bout turning them over, but they would be coated with varnish or wax to seal the air out of them. They would last quite a long time that way.