Why do eggs sometimes crack when you boil them?

[debbz1969]

When I'm boiling an egg and place it in the boiling water it sometimes crack and all the inside is soon on the outside!!!
It doesn't happen every time, I make sure the egg isn't cracked and I don't keep my eggs in the fridge so they are room temp. Any ideas, It really pickles me off!!!
TIA

[CAJ1]

If you put salt in the water before you put the eggs in it stops them cracking.

[Rollo]

This tends to happen if the egg is a little old.

Don't put the egg into boiling water. Put it into cold water and bring it up to the boil.

[debbz1969]

how do you time it if you put it in cold water? I meant for a soft boiled egg, to dip soldiers in...mmmm

[joggerjayne]

This is the reason ...

At the flat end of the egg is a pocket of air. If the egg had been fertilised, this would have been used by the embryo.

When you put the egg in hot water, this air expands, and splits the shell.

How do you avoid this?

Easy. With the tip of a sharp knife, make a tiny hole on the flat end of the egg. When you put it in the hot water, as the air expands it bubbles out through the hole.

Your eggs will never crack again ... guaranteed.

You can buy "egg prickers" from kitchen utensil shops. I have one, but I tend to just use a knife.

[Rollo]

If I was going to boil it for, say, 4 minutes in boiling water then I would boil it for 3 1/2 minutes once the cold water had come to the boil.

Once the water has started boiling turn down the heat so that the water is just gently rolling, not bubbling fiercely.

A little trial and error and you will find out how long you need to boil the egg to get it the way you like it.

Larger eggs take a little longer than small ones, of course.

[debbz1969]

wow JJ.... mucho impressed!!!!!
Will definately try that and report back in due course.
Thanks for that.
However... still laughing about the egg pricker gadget... and the fact that you own one....lol

[glasman]

So, Jayne, if you've got a flat end on your eggs, you don't need egg cups either.
Verrrrrrrry handy.

[joggerjayne]

It's like a little saucer with a hole in the middle. You press the bottom of the egg down on to the hole, and a little spike pops up and pricks your egg.

It does work. When you see how much air bubbles out of the bottom of the egg, you'll understand why they crack!

By the way ... none of the "eggy" bit bubbles out of the hole, because the film of white skin (between the shell and the egg white) goes up around the "egg" side of the air pocket, so all that comes out is the air.

This pocket of air also explains why a rotten egg floats bottom end up ... the gas which is created when the egg goes bad accumulates in the air pocket, and makes that end more buoyant.

glasman ... yeah yeah, okay ... obviously it's not totally flat.

Hi, Knobby

[happy_face]

Rollo - doing it the way you explain means you're tied to the cooker as you have to stand and watch exactly when the water starts boiling so you can start timing it. Doesn't that bother you?

[joggerjayne]

Incidentally ...

Rollo says that eggs can crack if they are a little old.

Rollo is absolutley correct.

If an egg is old, it may have started to become a little bit "gassy" inside.

The more gas there is in the egg, the more it expands, and the more likely it is to crack.

So ... accurate observation by Rollo.

[joggerjayne]

Knobby, I'm ...

Jayne
"The Anorak"
Brighton

=0)

Most of the eggs I eat are raw, whisked into a milkshake, so it doesn't matter about cracking ... although it's better if they're fresh !!