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