The Advantages of Poor Conductivity

Appears in
On Food and Cooking

By Harold McGee

Published 2004

  • About
The poor conductivity of ceramic materials is an advantage if the cook needs to keep food hot. Good conductors like copper and aluminum quickly give up heat to their surroundings, while ceramics retain it well. Similarly, ovens with ceramic (brick) walls are unparalleled for the evenness of their heating. The walls slowly absorb and store large quantities of energy while the oven is heated up, and then release it when the food is placed inside. Modern metal ovens can’t store much heat and so must cycle their heating elements on and off. This causes large temperature fluctuations, and can scorch breads and other foods that are baked at high temperatures.