Almost everyone has been faced with this conundrum — you reach into the fridge for an egg, but can’t remember how long they have been sitting there.
It’s true that over time, an egg’s quality begins to decline as the air pocket inside gets larger and the whites get thinner. However, an egg only “goes bad” when it starts to decompose because of bacteria or mold.
In fact, your eggs may be perfectly good to eat for many more weeks.
如有疑问，您可以使用几种方法来确定您的鸡蛋是好还是坏。这是前五名。
判断您的最简单方法之一蛋仍然很好，是检查纸箱上的日期。但是，如果您在此日期到达后立即将冷藏鸡蛋扔掉，您可能会浪费完美的鸡蛋。
In the US, eggs may be labeled with either a “sell by” or expiration date, depending on which state you live in, in order to let you know if your eggs are still fresh.
“按卖”日期表示商店应该提供多长时间出售的鸡蛋 - 包装后不超过30天 - 但不一定是鸡蛋变坏（1）。
An expiration date, on the other hand, marks the date after which the eggs are considered less than fresh.
If neither of these标签is present, there is yet another date you can look for to tell how fresh your eggs are.
由USDA分级的鸡蛋必须在纸箱上显示“包装日期”，这是鸡蛋的分级，洗涤和包装的日子。但是，如果您不知道要寻找什么，您可能不会意识到它。
包装日期是印朱利安日期,代表我ng each day of the year is represented by a corresponding, chronological number. Therefore, January 1st is written as 001 and December 31st as 365 (1）。
If your eggs are still within the expiration or “sell by” date on the carton, or within 21–30 days after the “pack date,” you can be pretty sure they are still fresh.
And even though the quality of an egg may start to decline after a certain date, it may still be good to eat for several weeks — especially if it has beenrefrigerated,保持质量,防止细菌的growth (2）。
但是，如果您的鸡蛋已经超过纸箱上印刷的日期，则可能需要使用另一种方法来判断鸡蛋是好是坏。
概括：Checking the “sell by,” expiration or “pack date” on an egg carton can tell you if an egg is still good. But just because an egg has passed its date does not always mean it has gone bad.
嗅探测试是最古老，最简单，最可靠的方法，即说一个鸡蛋是否变坏了。
If you find that your eggs are past their “sell by” or expiration date, you can tell if they are still good with a simple sniff.
变坏的鸡蛋都会散发出明显的气味，无论它们是否是生的或煮熟（3）。
If you can’t already tell while the egg is in the shell, crack the egg onto a clean plate or bowl and give it a sniff.
If anything smells off, toss the egg and wash the bowl or plate with hot, soapy water before using again.
如果情况闻起来正常，这意味着根本没有气味，那是一个好兆头，表明鸡蛋仍然可以安全使用（3）。
概括：嗅探生鸡蛋或煮熟的鸡蛋是一种简单但可靠的方法来判断鸡蛋是否变坏。
除了鼻子外，您的眼睛是告诉鸡蛋是好还是坏的有价值的工具。
当鸡蛋仍在外壳中时，请检查外壳是否没有破裂，粘性或粉状。
Sliminess or cracks can indicate the presence of bacteria, while a powdery appearance on the shell may indicate mold (4）。
如果外壳看起来干燥且未损坏，请在使用前将鸡蛋裂成干净的白色碗或盘子。在蛋黄或whites，因为这可能表明细菌生长（3，，，，4）。
如果您发现任何变色的迹象，请在测试新鸡蛋之前用热肥皂水扔掉鸡蛋，然后用热肥皂水清洗碗。
You can also check to see if the whites or yolk of the egg are runny. This is an indication that the egg is old and that the quality has declined. But this does not necessarily mean it has gone bad, and it can still be perfectly fine to use (4）。
概括：除了嗅探鸡蛋外，还要检查其外壳是否有细菌和霉菌的迹象。检查白色和蛋黄是否变色也是一个很好的策略。
浮点测试是检查鸡蛋是好还是坏的最受欢迎的方法之一。
This is also a common method for determining the age of a fertilized egg that is developing into a chick (5，，，，6）。
判断未施用的桌子鸡蛋是否新鲜。
To perform the float test, gently set your egg into a bowl or bucket of water. If the egg sinks, it is fresh. If it tilts upwards or even floats, it is old.
This is because as an egg ages, the small air pocket inside it grows larger as water is released and replaced by air. If the air pocket becomes large enough, the egg may float.
While this method may tell you whether an egg is fresh or old, it doesn’t tell you whether an egg is good or bad (3）。
鸡蛋会下沉而仍然很糟糕，而漂浮的鸡蛋可能仍然可以吃（3）。
概括：检查鸡蛋下沉或浮子是检查其新鲜的一种流行方式。但是，它无法告诉您鸡蛋是否变坏了。
Candling is a method used either to assess the quality of a table egg or to assess the development of the chick in a fertilized egg.
这是使用专业设备在工业上完成的，以确保将鸡蛋卵包装到包装之前。
But it can also be done on your eggs at home, if you’re willing to learn.
您需要一个黑暗的房间和一个小的明亮的光源。过去，使用了蜡烛，因此名为“烛台”。但是，使用小手电筒或阅读灯可能更有效。
将光源固定到鸡蛋的大端。然后，将鸡蛋倾斜，然后从左到右迅速转动。如果正确完成，则应照亮鸡蛋的内容物（7）。
这使您可以查看鸡蛋的机牢房是大还是大。在非常新鲜的鸡蛋中，空气牢房应比1/8英寸或3.175毫米薄。随着鸡蛋的年龄，气体取代通过蒸发而流失的水，空气口袋将变得更大（7）。
您还应该能够通过将鸡蛋从一侧移到另一侧来分辨，蛋清和蛋黄are. Less movement indicates a fresher egg (7）。
Candling may require some practice, but it allows you to reliably identify if an egg is fresh or old. Yet, like the float test, it cannot tell you if an egg has gone bad.
概括：Candling is a more difficult but reliable way of checking how fresh an egg is. However, it doesn’t tell you if an egg is bad.
缺乏关于如何分辨鸡蛋何时变坏的知识会导致某些人不必要地扔掉好鸡蛋。
在此处列出的五种策略中，打开一个鸡蛋，使其闻到嗅探并检查变色是确定新鲜度的最终方法。
请记住，含有引起食物传播疾病的细菌的卵，例如沙门氏菌，，，，may look and smell completely normal.
因此，不要忘记，即使鸡蛋通过了这些测试，也很重要fully cook it在食用之前，要达到安全的温度。
