Only eggs from kosher fowl are kosher. These include chicken, Cornish hens, ducks, geese, and turkey.
The prohibition of eating blood applies even to the smallest drop of blood, and thus any blood spots found in an egg renders the egg non-kosher.
Each egg should be opened into a clear dish or glass and checked for blood spots before it is cooked or combined with other food. If a blood spot is found, the whole egg must be discarded, and the cup or dish should be immediately and thoroughly washed with cold water.
When boiling eggs, it is customary to boil at least three eggs at a time. Some people have a separate pot just for boiling eggs.
If a blood spot is found in a boiled egg, the whole egg must be discarded.