Sunlight-cured tobacco, Bastam, Iran Curing and subsequent aging allow for for your slow oxidation and degradation of carotenoids in tobacco leaf. This generates particular compounds from the tobacco leaves and gives a sweet hay, tea, rose oil, or fruity aromatic taste that contributes on the "smoothness" of the smoke. https://broadfar.com/oraco-pioneering-a-smokeless-future-with-innovative-nicotine-delivery/