How come eggs sometimes crack when you boil them?

They expand in the shell.

My Grandmother used to say to prevent this you wet the eggs first before putting them in the water. (I am not a cook so I cannot tell you if this is correct)

As to why She felt it was the sudden change of temperature on the dry shell.

@jca

Start the eggs in COLD water—- Then bring to a boil and simmer.
Do not not use a rolling boil.
On the round end of the egg poke a pin in the end BEFORE putting in water.

I put the eggs in the water and then start it boiling. Haven’t lost an egg that way, yet.

Heat plus movement. To prevent them from cracking, you need to reduce temperature difference and prevent eggs from bumping at each other. Say, let the eggs sit in the tap water in the pan for a while so the eggs would warm up to room from the fridge temperature before heating up the water. And, try to use a large pan so you don’t stack the eggs. After they are done, handle them carefully.

@bengalileogirldrew (or @galileogirl) The questions are there, click on the meta tab, there’s a whole slew of em.

I think i would crack, if i were boiled.

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It would not be Easter, without a few colored cracked eggs.

I agree with people above, you should start the eggs in cold water.

I regularly cram too many eggs into too small a pan*, put them from the fridge into the luke-warm water I get from the hot tap without letting it run, and boil them all at once. Often it goes well. Sometimes one or two out of nine leave the pan cracked.
I always assumed those were the eggs that already had a minor crack before cooking, which cracked further. At any rate the cause would have to be something that’s different for the cracked eggs than for all the other ones…

If all your eggs crack, do you add salt to the water?

* High protein diet. Nine eggs a day five days a week.

It’s the eggs bouncing around in the pot while at a rolling boil. Turn down the burner when it just gets to a boil. The rolling boil is no hotter than barely boiling, but is knocking the eggs around. Any heat input more than barely boiling is only making more steam in the kitchen, not cooking the eggs any faster; just wasting energy and damaging eggs.

I want to start a movement. NO MORE EASTER EGGS!

The Easter Quiche! Now that’s the ticket.

I like @chazmaz ‘s idea. Bizarre-colored quiche, I’m going to try this!

The Joy of Cooking says to drop eggs into boiling water, but to cook at no more than a bare simmer. I get perfectly cooked eggs this way, but I do get the occasional crack.