Sun-curing
- Sun-curing is the least common method of curing tobacco.
- Oriental tobacco grown in the regions of Europe and the Middle-East are cured this way. The leaves are stored in bulks until fermented and then moisture is added.
- The characteristic reactions that occur during sun-curing are the considerable loss of starch with production of sugars and its fermentation and the formation of soluble nitrogenous constituents at the expense of protein.
- They have low sugar and low nicotine content and are used in pipe blends, chewing, cigar tobacco and Turkish cigarettes.
There are several modifications in sun-curing.
- Curing whole plant on racks as in cigar and chewing tobacco. After initial wilting in the field, the plants are strung on bamboo poles and cured in sun. The entire process takes about 15-20 days.
- Curing leaves with pieces of stem on racks as in Natu tobacco. In this method, racks are not exposed to direct sun, thus, it takes longer period (6-8 weeks).
- Curing whole plant on the ground as in bidi and hookah tobacco. In this curing, leaves are allowed to dry in the sun on the ground and are turned over twice a day. The process continues for about a week and then heaps are made that are opened on the next day and re-heaped. This process of heaping, opening of heaps, spreading and re-heaping continues for about 10-15 days. By the end of this period the leaves become completely cured.