How do I know if an egg is fertile?
You need to shine a bright light through the egg in a dark room. If done infrequently, you can use a flashlight.
Use a candling light as shown in our Equipment Section if you will do it often or you want to ensure accuracy.
By seven days, you should see a darker yolk, veins under the shell and the beginnings of an embryo.
Go to our candling pictures to know how they should look. You can break a fresh egg to know if it is fertile but then you can't incubate it.
If the white spot on the yolk is donut shaped, it is fertile. If it is irregular and solid, it is infertile.