I'm getting ready to smoke my first Butt on my recently purchased smokette. I was wondering if most people trim any fat before starting or leave it as is? Also, I've always heard of the fat rendering out on a long, slow cook. When you smoke the butt for, as I've read here, 17 - 20 hours or more, when you pull the pork is all the fat rendered, or is there some that still needs to be separated. I guess I would find out when I'm done, but I was curious what to expect.