Hvorfor sprekker egg i kokende vann?

[eplekasse]

Jeg opplever fra tid til annen at egg sprekker under koking, selv om de legges i kaldt vann. Noen årsaker til dette? Trodde det kun skjedde hvis man slapp dem rett i kokende vann.

[Gavekort]

Why do eggs crack? How can I prevent eggs from cracking while boiling?

The bottom, rounded end of an egg contains a small air bubble. As the egg heats up, the air inside the bubble expands. As the hot air pushes outwards, it puts pressure onto the shell, making it crack. You can prevent this by making a pin-pick in the bottom rounded end of the egg. This will let the expanding air escape.

You can also prevent cracking by letting eggs come to room temperature before cooking them. Add the eggs to tap water and then apply the heat. Do not add eggs directly into boiling water.

Adding either salt or vinegar in the water will not prevent the egg from cracking but will congeal the white if it starts to leak out of the shell from a small crack, making the cracked egg, still pleasing to look at.

 

http://www.scienceofcooking.com/eggs/boiled_eggs.htm

[StoreMyen]

Trykkforskjell.

Et hull i den butte enden helper. Det finnes spesialverktøy for dette.

Salt i eggvann høres bortkastet ut, men det hjelper mot at eggehviten koker ut av skallet om egget skulle sprekke.

[democomputer]

Selv er jeg veldig fornøyd med damp-metoden https://www.youtube.com/watch?v=v_dlr-YKW40

Mine anekdotiske bevis sier at det sprekker sjeldnere nå etter jeg skiftet til denne metoden.

 

K