Solar-cured tobacco, Bastam, Iran Curing and subsequent growing old allow with the sluggish oxidation and degradation of carotenoids in tobacco leaf. This makes particular compounds inside the tobacco leaves and gives a sweet hay, tea, rose oil, or fruity aromatic taste that contributes into the "smoothness" from the smoke. https://broadfar.com/non-combusted-cigarettes-a-safer-alternative-or-just-a-myth/