Pat your beef brisket completely dry with paper towels — this matters more than you'd think. Season both sides generously with salt and pepper. You're literally creating the flavor foundation right now.
Mix together your BBQ sauce, tomato paste, apple cider vinegar, brown sugar, beef broth, onion powder, garlic powder, liquid smoke, and Worcestershire sauce in a bowl. Whisk until the tomato paste breaks down and everything combines smoothly. This sauce blend is what makes your slow cooker BBQ brisket family dinner actually special.
Place the brisket in your slow cooker fat-side up. Pour that sauce mixture all over and around it. The slow cooker does the heavy lifting now — I love this part where you can actually walk away.
Cover and cook on low for 8 hours. Don't peek constantly (I know it's tempting). After about 7 hours, you can quickly check that it's getting tender.
After 8 hours, the meat should shred with a fork easily. If it's still tough, give it another hour — every slow cooker runs different temperatures. Remove the brisket and let it rest for 10 minutes on a cutting board.
Shred the beef using two forks or pull it into chunks. Return it to the slow cooker with all that beautiful sauce. Stir everything together so the meat gets coated throughout. This is where the whole slow cooker beef brisket transforms into something incredible.
Taste and adjust seasonings if needed — sometimes I add a pinch more salt or a splash more vinegar depending on my BBQ sauce. Add smoked turkey slices if you're using them and let everything heat together for about 5 minutes on high.