Boiling water can be a lifeline in a crisis, and it’s a cornerstone of cooking. Yet for many, the act of doing it is still a mystery. This week, some 8.5 million Texans are being asked to boil their drinking water. In a repeat conversation, food writer Kenji López-Alt describes what a miraculous thing it is to put a pot of water on the stove and watch it transform from a placid surface to kinetic chaos.