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