Double yolk eggs form when a hen releases two yolks from her ovary close together. Normally, a hen releases one yolk at a time. The yolk then travels through the oviduct, where the egg white, membranes, and shell form around it.
Sometimes, two yolks develop and release from the ovary at nearly the same time. Both yolks then enter the oviduct together and continue through the egg-forming process. The egg white, membranes, and shell form around both yolks, resulting in one egg with two yolks.
Why Do Hens Lay Double Yolk Eggs?
Double yolk eggs occur more often when a hen first begins laying eggs. Young hens are still developing a regular ovulation pattern, which can sometimes cause two yolks to be released close together.
These eggs also tend to be larger than regular eggs and are commonly associated with extra-large or jumbo sizes.
Can You Buy Double Yolk Eggs?
You can find double yolk eggs at some grocery stores, but they are not available on a regular basis. If you’re looking for them, ask your local grocery store manager about their egg delivery schedule.
In Canada, cartons labelled as double yolk must contain at least 50% eggs with two yolks, according to the information provided by Egg Farmers of Ontario.
Learn more about double yolk eggs from Ontario egg farmer Cindy in the video below.