Is It Kosher?
By Rabbi Eliezer Eidlitz — a comprehensive guide to the kosher status of hundreds of common foods, ingredients, and food categories.
Eggs and Egg Substitutes
The basic rule of kashrus is that the product of a non-kosher animal is not kosher. Therefore, all eggs from non-kosher birds are not kosher. To be kosher, eggs must come from kosher fowl and be free of bloodspots in the white (albumin) and the yolk. Each egg must be checked individually after it is opened. If there is blood in an egg, it is forbidden.
Today most eggs are non-fertilized. Reb Moshe Feinstein ZT"L states that concerning unfertilized eggs, only the blood spot within them would have to be removed, not the whole egg. Therefore, if one buys an egg from the store in the United States, it can be considered a kosher egg, even without checking it. However, it is common custom to check all eggs for bloodspots.
Egg Substitutes: Two types of egg substitutes are available. The general public can purchase egg substitutes made from egg whites, vegetable oil, nonfat dry milk, emulsifiers, and artificial flavors — no problems if individual ingredients are kosher. Commercial bakeries use various egg substitutes that may include extracts from kosher fish or milk derivatives, all of which can be produced under kosher supervision.
Another cheaper substitute for fresh whole eggs is the ova, the egg found in a hen after slaughter. These are non-kosher eggs and present a serious kashrus problem. Products listing powdered or frozen eggs as ingredients must have supervision.