Yong-ki Pak
I've tried a dozen of ways to get the hard boiled eggs perfectly. The main difference is boiling eggs in the cold water or in the boiling water. For me, boiling water first worked. When the water boiled I lowered the heat a bit to prevent eggs cracking. Then timed between 6 minutes and 12 minutes. 6-7 minutes for a bit soft hard boiled eggs, and 10-12 minutes for hard boiled eggs. I also had eggs in the cold water to stop cooking.