I have recently taken up pipe smoking. I would like to know if there is any problem with the tobacco one can buy for the pipe. Many ingredients are used to process and flavour the tobacco leaf. How can we be sure they are kosher? Indeed, I have seen pipe tobaccoes where non-kosher wine is added as a flavoring.
On the other hand, perhaps due to the burning of the tobacco it becomes permissible? In fact, this same basic question can be posed regarding cigarettes. Do cigarettes require a hechsher to ensure that all the ingredients are acceptable, and if not, why not?
Tobacco is completely inedible and unfit for consumption [eating] all additives are rendered unedible as well in the mixture. Hence, there is no kashrus concern with inhaling it’s smoke [which would be questionable even if the source was edible].
See Minchas Asher Haggadah Shel Pesach at the end for a lengthy discussion on this topic.