Double Boiler

Technique Type: Heat

A double boiler, also known as a bain Marie, is a stove top apparatus used to cook delicate sauces such as beurre blanc, to melt chocolate without burning or seizing, or cook any other thick liquid or porridge that would normally burn if not stirred constantly. It consists of an upper vessel containing the substance to be cooked that is situated above a lower pot of water. When brought to a boil, the steam produced in the lower pot transfers heat to the upper pot.

Source: http://en.wikipedia.org/wiki/Double_boiler