Yep I use this trick all the time: - Put them in already boiling water. - boil for 7 mins - then take them out and keep them under a running tap of cold water.

Yep I use this trick all the time: - Put them in already boiling water. - boil for 7 mins - then take them out and keep them under a running tap of cold water. You want the water running so it gets maximum heat transfer. I think it might be to do with how the shell and membrane have difference expansion coefficients. Or the membrane and the egg white. Not sure.