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