Rooster & Hen Hatching

[McChooky]

Research has shown the male embryo is more vulnerable to cold temps than the female. The males die in the shell.

I'm not sure what you mean by "cold storage method." Generally, the eggs I'm going to incubate are kept in the basement until I have enough. It's about 65°F down there, instead of 70°F upstairs. A couple of times, I didn't have enough, so I grabbed some out of the fridge. They were in the fridge for anywhere from a few days to three weeks. My hatch rate was definitely down a bit, but most hatched. I didn't keep them, so not sure of the sexes of any.

Brinsea even recommends that if we have a power outage expected to be two or more hours and we're in the first 0-14 days of incubation, to put the eggs in the refrigerator. I would not do this though and would just cover the incubators. We also have a generator we'd get running to power up the incubators.
https://www.brinsea.com/t-poweroff.aspx#:~:text=If you experience a power,More Information & Species Differences

They were stored in a refrigerator