How does a breeder keep eggs fertile?

[IrisJade]

Just bought some eggs off a breeder, they tell me they have 4 eggs available and some will be laid later for the rest ive bought, Does this delay the time of them hatching successfully, idk how one keeps eggs ready in my mind once they have been laid its best to incubate right away no?

 

[sourland]

A general rule of thumb is within 10 days of being laid, but just think how long it takes a hen to build a clutch before incubating them. I have successfully held eggs up to 21 days with successful hatch %.