Washing can introduce bacteria because it can remove the protective layer on the egg.
A person in this thread says she doesn’t set dirty eggs:
https://www.backyardchickens.com/threads/washing-hatching-eggs.1210930/
I once had a dirty egg with about a dozen eggs that looked clean. None of the clean eggs hatched but the dirty one did. My guess is the dirty one might’ve contaminated the other eggs but I don’t know if those ones were cleaned by the seller. My guess is no or they would’ve cleaned the dirty one too.
As for the egg that looks older have you tried candling it to see if it has an embryo? I’ve done staggered/hatches of different stages and they worked out ok.
A person in this thread says she doesn’t set dirty eggs:
https://www.backyardchickens.com/threads/washing-hatching-eggs.1210930/
I once had a dirty egg with about a dozen eggs that looked clean. None of the clean eggs hatched but the dirty one did. My guess is the dirty one might’ve contaminated the other eggs but I don’t know if those ones were cleaned by the seller. My guess is no or they would’ve cleaned the dirty one too.
As for the egg that looks older have you tried candling it to see if it has an embryo? I’ve done staggered/hatches of different stages and they worked out ok.

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to you...


