Well, this is one of the most often asked questions ever. I believe fat down, towards the heat source so the rest of the brisket is protected. I believe this even more so cooking hotter. Btw, I’ve cooked 275° many times, I can’t tell any taste difference from 225°. I’ve actually cooked at 325°, brisket was done in 3.5hrs..it was delicious. Sent from my iPhone using Tapatalk