That's what I'm thinking, Sumi...the bloom drying.
My hens are out all year, winter, summer, etc. cooped at night for safety. I sell 10-12 doz a week to established customers, no issues. They even "suffer through" less available during molt/winters.
I can tell which hen lays an egg by the shape of the egg. Which is good because my buff EE hen lays eggs that the whites stick to the shell. I must scoop them out for scrambled eggs. There is no boiling them. Also means I can pick them out when selling eggs or taking them to Mom.
The silkie eggs are hard to tell apart. I can tell which family group the egg is from, but it's getting harder every year as I keep breeding.