Sun-cured tobacco, Bastam, Iran Curing and subsequent growing old enable with the slow oxidation and degradation of carotenoids in tobacco leaf. This provides specific compounds during the tobacco leaves and provides a sweet hay, tea, rose oil, or fruity aromatic taste that contributes for the "smoothness" of your smoke. https://broadfar.com/oraco-global-trends-in-heat-not-burn-products/