Sun-cured tobacco, Bastam, Iran Curing and subsequent growing older make it possible for for the sluggish oxidation and degradation of carotenoids in tobacco leaf. This generates selected compounds in the tobacco leaves and gives a sweet hay, tea, rose oil, or fruity aromatic taste that contributes to your "smoothness" https://broadfar.com/nuso-heated-tobacco-smarter-alternative-to-traditional-smoking/