Did my first yesterday, a 6 lb brisket and don't know why it was so bad. I only trimmed the couple hard spots of fat,cooked at approx 231° for approx 8 hours. I foiled at 155° and cooked till 190° did the toothpick test and it was very tough. Tooth picked again at 198° was tough. Pulled it out at 205° thinking either something was wrong or I can't use a tooth pick. I poured a coffee cup of liquid out of foil and that was the only moisture in the brisket it was disgustingly dry! Just checked the accuracy of my thermometers a couple days ago. Don't know what went wrong! Any info would be great.