I think you are going to find some different answers to this question on this forum. Ultimately it comes down to your personal taste which, if you're a newbie like me, will take some time and experimenting to develop. Some people on this forum bake their herb at 290C, others at 340C or 350C. Some people here bake their herb only once, others as much as four or five times. It's one of the beauties of vaporizing that I have come to appreciate...and I still haven't figured out what I like best because there is so much you can tweak! I'm still baking mine at 350C and getting two good bags and one half-ass bag before it is done. One reason I'm not messing with that formula yet is I'm still trying several different strains and I want to focus on the herbal differences, not the vape variables. The one stopping point you should probably heed is to stop when your herb is very dark. The Extreme won't let you burn it, so don't worry about vaping it too much. Mine usually looks medium brownish when I am done...not tan and not dark. But again, that's me. Figure out what you like...go too far, stop too soon, etc. In the end, it's all about the high!