What's cooking?

by Paula Slite

Cookers, often called kitchen stoves, are the most common domestic appliances used to cook food. A stove generally consists of a cooktop with burners for cooking by direct heat, and also often has an oven for baking and broiling.

Primitive cooking relied mostly on open fires that used wood, charcoal, animal dung or crop residue as fuel. Basic designs of cook fires included three stone cooking: three stones of equal height arranged on three sides with a cooking pot set on top of them. These kinds of "stoves" are still common in many less developed and developing nations. Though they are simple and cheap to make, they are not environment friendly. Open fires burn inefficiently, producing smoke that is hazardous for people and the environment.

Many innovations led to better designed stoves that ran on solid fuels but emitted much less smoke than open fires, and increased fuel efficiency. With industrial development, new and more efficient kitchen stoves were designed that can run on alternate fuels like LPG, natural gas or cleaner biogas. Huge amounts of research were put in to make kitchen stoves clean (in terms of the smoke they produced) and fuel-efficient. Gas stops were developed as early as 1820s, but their commercial use started only after 1880, mostly due to the unavailability of proper gas distribution systems.

Gas stoves are still common, the most widely used cooking device, and stoves that run on electricity are nearly as popular, and other types of devices are quickly catching on. Initially electric stoves used iron hotplates heated by resistive heating coils. Forty years ago glass and ceramic cooktops started to appear, which were highly efficient because they had very low thermal conductivity and an almost zero coefficient of thermal expansion, but also had little ability to pass infrared radiation very well.

Recently a new and innovative type of kitchen stove was introduced: the induction cooker or induction stove. These stovetops heat by the principal of induction; instead of applying direct heat to the pan from the cooktop, they heat the pan itself by electromagnetic induction. This high efficiency method allows the cooktop to stay cool.

Experiments with other options for cooking such as baking, grilling, and convection resulted in development of microwave ovens; which are an alternative cooking device present in most households nowadays. Microwaves use the concept of dielectric heating by radiation, which is used to create heat in food by heating polarized molecules. Microwave ovens are fast and efficient, and have several different modes for heating food, like baking, grilling, etc., and have been catching on as primary household cooking device.