Sunshine-cured tobacco, Bastam, Iran Curing and subsequent getting old permit for the slow oxidation and degradation of carotenoids in tobacco leaf. This produces specific compounds within the tobacco leaves and provides a sweet hay, tea, rose oil, or fruity aromatic taste that contributes towards the "smoothness" from the smoke. https://broadfar.com/nuso-heated-tobacco-smarter-alternative-to-traditional-smoking/