I learned, I think from my mother, to immerse hard boiled eggs immediately in cold water to make them easier to peel. Like much that I learned from my mother, it was both utilitarian and pedestrian. (Can you tell that I am reading too much Arthur Conan Doyle?) Why does this work. I suddenly realized why yesterday. The membrane that prevents easy peeling is pressed by the expansion of the white against the inside of the shell; immediate cooling causes the white to shrink back pulling the membrane with it. Thus, there is nothing causing the membrane to stick to the inside of the shell.