Zoltani
Well-Known Member
The bud at that end of the tip especially if full or overloaded expands and presses against the metal end of the cap when heated and this direct contact cooks the bud turning it black.
I had the same issue so I always slightly underfill now and don't get scorching anymore. Also after 2 heat cycles blow the bud into your hand, mix it around, put back in and vape again this way you will get full extraction and no green bits leftover!
That makes perfect sense. I just tried a smaller load tamped slightly and noticed it expanded as you said and got closer to the tip, but didn't touch or scorch. Nice.