Ceramic is second oldest form of cookware, right after the large flat rock.
Ceramic comes in two forms: glazed, like porcelain and unglazed, like terra cotta; both are insulators. Glazed ceramic is non-reactive and non-porous, however some glazes have been made with high-concentrations of lead, so if you are unsure of the origin of a pan take it to your local extension office to be tested. Unglazed ceramic is porous, liquids can leech into the pan and stain it. Some pans like the Römertopf use that as a feature requiring you to soak the pan in water before use allowing it to absorb water which it can release to steam the food as it cooks in the oven.
