The combination of its capacity to hold heat plus its weight means that cast iron is slower to heat. However, once it is heated, it retains its heat, an advantage over pots made of other metals. Because cast iron holds heat well and distributes it evenly, you ordinarily do not have to use high temperatures. Tabitha Alterman, writing in "Mother Jones," says that by preheating a cast iron Dutch oven, you can get the same results as expensive stone hearth ovens used by baking professionals.
Heat in a cast iron pot or pan travels more slowly than in those made of aluminum or stainless steel. If you put a large cast iron skillet on a small burner, the inside of the skillet will get hot and the outside will remain cool. If possible, you should use a burner the same size as your skillet. If you heat cast iron in the oven, it will heat evenly.
High Temperature Seasoning
When unsaturated fats are heated at high temperatures, they break down and are oxidized, forming larger molecules that join with bits of carbon and other impurities forming a smooth layer on cast iron that prevents food from sticking. This is known as “seasoning” cast iron cookware. You will need temperatures between 400 and 500 degrees F to give a cast iron pan a smooth, black surface that is truly nonsticky. Temperatures of 350 to 375 degrees will only yield a brown, partly sticky surface.
Extreme High Temperatures
If you abuse or neglect your cast iron pot, you may want to strip it down to bare metal and re-season it. To do this, you will have to heat your pot to about 800 degrees F. To help keep the surface smooth and make it more durable, use metal cooking implements that gently scrape the bottom.
Lodge, which makes numerous kinds of cast iron cookware, markets a cast iron pizza pan that weighs 9 pounds 14 ounces and is designed to be used at oven temperatures of 550 degrees F.
Enameled Cast Iron
If you use a cast iron pot or Dutch oven that is covered with enamel, you should use it in an oven below 400 degrees F.