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