Cooking on a three stone stove is a traditional method of cooking. It is the cheapest stove to manufacture, requiring only three suitable stones of the same height on which a cooking pot is balanced over a fire. This is a very basic stove heated by burning wood or fossil fuels. 


Three stone cooking stove
[Image source]

An average rural family in a developing country like India spends 20% or more of its income purchasing wood or charcoal for cooking. Living in the city does not help much as the urban poor frequently spend a significant portion of their income on the purchase of wood or charcoal.

This cooking method has many problems:
• Smoke is vented into the home, instead of outdoors, causing health problems.

• Fuel is wasted, as heat is allowed to escape into the open air. This requires more labour on the part of the user to gather fuel and may result in increased deforestation if wood is used for fuel.

• Only one cooking pot can be used at a time.

• The use of an open fire creates a risk of burns and scalds. Especially when the stove is used indoors, cramped conditions make adults and particularly children susceptible to falling or stepping into the fire and receiving burns. Additionally, accidental spills of boiling water may result in scalding, and blowing on the fire to supply oxygen may discharge burning embers and cause eye injuries.

The World Health Organization has documented a significant number of deaths caused by smoke from home fires. The negative impacts of such a process of cooking can be reduced by using improved cook stoves, improved fuels (e.g. biogas, or kerosene instead of dung), changes to the environment (e.g. use of a chimney), and changes to user behaviour (e.g. drying fuel wood before use, using a lid during cooking).

This cooking stove is still the most popular in the rural areas and to some extent with the urban poor in India.