Why do eggs expire?

Answer 1

Eggs may contain Salmonella Enteritidis (SE) bacteria that can cause foodborne illness. While the number of eggs affected is quite small, there have been cases of foodborne illness in the last few years. To be safe, eggs must be safely handled, refrigerated, and cooked by their expiration date!

http://www.fsis.usda.gov/Fact_Sheets/Focus_On_Shell_Eggs/index.asp

Answer 2

Eggs will loose moisture during storage causing the white to shrink. The proteins in the egg will also degrade over time the result will be an egg that spreads out instead of forming a compact shape when it is fried. Although the quality of the egg is affected it would still be safe to eat when cooked. The main reason for the expiration date on eggs to to insure that bacterial contamination will not have had a chance to make the egg unsafe. Also, The expiration date assumes that you properly refrigerate your eggs.

Answer 3

Foods are classified into "animal" and "vegetable"; each is further sub-divided into all the types of foods that people eat. Two foods, however, are neither animal nor vegetable: they are:
1) milk and
2) eggs.
Both are considered "mineral" (unless, of course, the egg has an animal embryo in it; then, of course, it is "animal").
Milk, unless pasteruized, even if well-refrigerated, will begin to sour (go bad) in about 3-4 days. Eggs, if kept cool, will generally keep (keep from going bad) for 3 - 4 weeks.
If you want to know, before cracking the egg, if it is good or bad, place into a bowl, bucket, whatever of water. Bad eggs (because of the gas produced when going bad) will FLOAT. If it partially floats, or even raises up from the bottom, consider it bad.

Answer 4

Um, because they lose their freshness and do indeed, eventually go bad. What? Did you think they were some type of immortal food?????

Answer 5

Because they're food?