Temp has to be 220 or above to melt the fat. Time is variable depending on wt, alt, phase of the moon, etc. I usually allow 10 to 14 hours for a brisket in a smoker depending on size. I use a cookshack electric smoker with a jar of water inside to keep the moisture up. Use your wood of choice. I'm partial to oak for beef, but yrmv. Longer times by themselves don't make a better product. You want the Fat to baste the lean meat. I keep water in there because I don't want to dehydrate the brisket. When selecting a cut of meat try to find one with so much fat that you swear you wouldn't eat that. As long as you are above around 220 the fat will cook off flavoring the meat.
