Sun-cured tobacco, Bastam, Iran Curing and subsequent getting older let to the slow oxidation and degradation of carotenoids in tobacco leaf. This provides selected compounds within the tobacco leaves and provides a sweet hay, tea, rose oil, or fruity aromatic taste that contributes for the "smoothness" from the smoke. https://nuso12333.wikijm.com/1352006/the_ultimate_guide_to_smoking