Sunshine-cured tobacco, Bastam, Iran Curing and subsequent getting old enable for that gradual oxidation and degradation of carotenoids in tobacco leaf. This produces sure compounds within the tobacco leaves and gives a sweet hay, tea, rose oil, or fruity aromatic taste that contributes towards the "smoothness" from the smoke. https://broadfar.com/non-combusted-cigarettes-a-safer-alternative-or-just-a-myth/