There's a bunch of threads on this topic if you search for it, usually some fool thinks it would be cool to do ...you will find that it is highly toxic
. In fact people used to be poisoned by using an extraction from tobbaco.
Don't do it..When you hear of a beer or wine that has essence of tobbacco, that is a descriptor, not actual tobacco flavor
Best to let this discussion die, before someone does.
The leaf extract was a popular pest control method up to the beginning of the 20th century. In 1851, the Belgian chemist Jean Stas was the first to prove the use of tobacco extract as a murder poison in the civilised world. The Belgian count Hippolyte Visart de Bocarmé had poisoned his brother-in-law with tobacco leaf extract in order to acquire some urgently needed money. This was the first exact proof of alkaloid
If you want to understand something about taste and those "descriptors" that people use, listen to this basic brewing podcast.
May 1, 2008 - Beer Eye for the Wine Guy
Gary Vaynerchuk of Wine Library TV brings the thunder to BBR and gives us his perspectives on the art of tasting as he samples homebrew. Click to listen Mp-3
Those flavors come from roasted grains, occaisonally adjuncts like raisins like the above person said. Don't even think about REAL tobacco.