from
wiki:
Flue-cured
tobacco was originally strung onto
tobacco sticks, which were hung from tier-poles in curing barns (Aus: kilns, also traditionally called Oasts).
These barns have flues which run from externally fed fire boxes, heat-curing the
tobacco without exposing it to smoke, slowly raising the temperature over the course of the curing. The process will generally take about a week.
This method produces cigarette tobacco that is high in sugar and has medium to high levels of nicotine. The Smith Tobacco Barn is an example of traditional, flue-cured tobacco barn.