DOUBLE YOLK EGGs

Most of us have had the experience of finding we have a double yolk egg. Depending on whether you're a yolk person or a white person it's either a bonus or a fault. Personally I think it's a bonus, but I love egg yolk more than white.

Double yolk eggs are actually fairly rare, about 1 in 1,000 for commercial eggs where consistency is required.

Rarer still are multiple yolk eggs, triples or even quadruples and apparently there has even been a nine yolk egg!

What Causes Double Yolk Eggs?

When an egg starts its journey inside the hen, the first thing formed is the ovum in the hen's ovary. This grows and the colour changes from pale grey to the yellow we know as the yolk colour.

Once it reaches full size, the yolk sac breaks away (ovulation) and begins a journey down the oviduct where the egg white (albumen) and the shell form around it. The process from ovulation to egg laying takes around 24-26 hours.

Normally, the next ovulation is triggered by the hen laying the egg but occasionally things go wrong and two yolks are released at the same time to travel down the oviduct together, being surrounded by one shell and giving us the double yolker.

Which Hens Lay Double Yolkers?

Most often double yolk eggs are laid by young hens of productive egg laying breeds. If you really like double yolked eggs then the highly productive breeds are more likely to reward you when young.

As they become more mature hens and their system settles down to correct production then the double yolks become less frequent to non-existent.

Since the double yolk egg cannot bring forth double chicks, genetically it is not possible to have a breed that consistently produces them. They'd die out! It is possible to develop a breed where the ratio of double to single yolk eggs is higher but I do not know of one.