Solar-cured tobacco, Bastam, Iran Curing and subsequent getting older permit to the sluggish oxidation and degradation of carotenoids in tobacco leaf. This creates certain compounds inside the tobacco leaves and offers a sweet hay, tea, rose oil, or fruity aromatic flavor that contributes to your "smoothness" from the smoke. https://broadfar.com/heated-tobacco-shaping-a-safer-sustainable-smoking-future/