Hi Bayarjargal,

This is a fantastic question - we're glad you asked it.

During grading, eggs are passed over a strong light known in a process known as candling. Candling searches for many things, including blood spots that may be present in the egg. The chances of blood spots in brown eggs is a little higher as their shells are darker and the pigment in the shell makes it harder to see during the grading process. Candling methods reveal most eggs with blood spots which are then removed, but even with electronic spotters, it is impossible to catch them all.

Blood spots are caused by the rupture of a blood vessel in the hen when the egg is forming, or by a similar incident in the wall of the oviduct. This is a natural process and the hen is not harmed when this happens. Both chemically and nutritionally, these eggs are safe to eat. If the spot is small, it can be removed with the tip of a knife before you cook the egg, if you wish. If it is a large rupture, although not harmful, it is not appetizing and for that reason it should be discarded.