Sunlight-cured tobacco, Bastam, Iran Curing and subsequent getting older allow to the gradual oxidation and degradation of carotenoids in tobacco leaf. This provides certain compounds inside the tobacco leaves and offers a sweet hay, tea, rose oil, or fruity aromatic flavor that contributes to the "smoothness" from the smoke. https://nuso11122.wikibyby.com/1324059/the_2_minute_rule_for_cigarettes