Edible Egg

Bird and fish eggs are common food sources. Fish eggs are known as roe or caviar.

The most commonly-used bird eggs are those from the chicken, duck, and goose, but smaller eggs such as quail eggs are occasionally used as a gourmet ingredient, as are the largest bird eggs, from ostriches. Eggs are frequently used in both sweet and savory dishes as a source of protein and/or to bind the other ingredients in a recipe together. Sometimes the whole egg is cooked together. Sometimes the egg yolk is used separately from the egg white.

Many who practice vegetarianism feel it is acceptable to eat eggs as the bird which lays the eggs is not killed. People concerned about animal welfare (especially vegans) are reluctant to eat battery eggs eggs as factory farming is considered cruel. Even free range eggs are sometimes unacceptable to those who are concerned about animal welfare as it is felt that alleged free range birds may not be much better off than battery birds.

Chicken's eggs

The primary cooking techniques for eggs are:

	baking
	boiling
	frying
	omelet's
	poaching
	scrambling
	soufflé
	egg salad

Eggs may also be pickled, hard-boiled and refrigerated, or eaten raw, though the latter is not recommended for people who may be susceptible to salmonella, such as the old, the infirm or pregnant women.

When eggs become rotten, the yolk will turn green and the egg will emit a sulfurous smell when broken. Although deemed offensive by most Western palates, fermented eggs are considered a delicacy by some in China, when prepared using a special method which includes letting them sit for three months to age (or rot, depending on one's interpretation).