Charcoal is produced by the carbonisation of hardwood in kilns at temperatures between 400 and 700 °C without exposure to air. This removes most of the water from the wood and increases its heating efficiency. Charcoal is a plant biomass that is non-polluting and environmentally friendly. Due to its properties and quality, charcoal is the most widely used in restaurants or garden barbecues. Charcoal adds a very specific aroma to the dish.