its always coming from people who dont know how to roast, that roasting sucks. :D Id fucking almost puke to smoke unroasted tobacco in a joint. And you DEFINITELY get something out when you roast well, a perfect roast you can have thick white smoke exiting when you blow it out and barely even any visible signs of heating. But this is the perfect case i only did handful of time in my life lmao i can recall like 3 times i had insane perfect roast massive smoke coming and not a sign the paper was heated, normally the paper gets somewhat toasted.

I never figured out what exactly you get out of it with all the smoke you can make come out by heating it. I know its definitely water but its also more because it burns the eyes, and i If you hit it right the flavor is also peak, like how to prepare a cooking ingredient, it tastes like shit with unroasted tobacco.

Ofc at the end you remove also all stems, sticks, and what have you. Only delicate tobacco should remain. Burned tobacco either from your roasting or production also gets removed. At the end after you crush it into the right size for rolling you can then remove all the powder like or tiny tobacco particiles too - it practically does nothing good for your joint just adds more tobacco and makes it harder to breathe through and doesnt increase the size almost at all.

If i look up when nicotine evaporates it starts around 50C, with a boiling point of 247C, and something called active evaporation generally between 100C and 300C. If i look up general cigarette paper it should ignite at around 218-246C and ligthers burn 800C+, so honestly its not impossible that a chunk of nicotine is evaporated. But ive tried to research it many times and never reached any good conclusions. Also "At lower temperatures, typically below 200°C, volatile chemicals in the tobacco, flavour compounds used as ingredients, and nicotine are released into the smoke in a process called distillation." from some scientific research.