I tried boiling hay in the oven or pan, not impressed. I was, until your method, greasing the item with crisco, turning it upside down in a oven at 350 for a hour, letting them cool on their own in the oven, this leaves them streaky at times, and not black, but more a honey colored. Your method with the preheating worked amazingly, less smoke, less smell, and a beautiful dark black color, the first go around.