Curing entails four essential steps: wilting, yellowing, colouring, and drying. These involve physical and chemical changes in the leaf and are regulated to develop the desired properties.
Air-Curing This process is used for Burley tobacco where tobacco is hung in unheated, ventilated barns to dry naturally until the leaf reaches a light to medium brown colour. At this point, there are virtually no sugars left in the leaf.
Flue-Curing The harvested leaves are dried under artificial atmospheric conditions by regulating the temperature and humidity to obtain leaves with desired qualities.
It is done in a specially constructed curing barn connected to a furnace. It takes around 4 to 6 days depend on leaf density.
Flue-Curing Barn: The barns for flue curing are small and tightly constructed with ventilators and metal pipes, extending from furnaces around the barn.
A ventilated structure, connected to a furnancer one side and air exhausters for air rotation. Inside wooden tiers are provided at different levels to hold the green leaves during curing. Firewood is the most commonly used as fuels for curing FCV tobacco.