Cover and cook on low for approximately 10 hours, checking for tenderness around the 8-9 hour mark.
Once the beef pulls apart easily with two forks, transfer it to a rimmed plate and shred. If it resists shredding, cover and continue cooking until tender.
Return the shredded beef and any collected juices to the slow cooker. Stir into the cooking liquid, cover, and continue cooking for the remaining 1-2 hours.
Taste and add more seasoned salt if needed. Serve with the cooking juices.
Notes
Substitutions: Use 4 cups of low-sodium beef broth instead of the water and beef base.
Cooking Time: Timing varies by slow cooker and roast thickness. Cook until the beef shreds easily.
Storage: Refrigerate with juices for 3-4 days or freeze for up to 3 months.
Reheat: Warm with juices on the stovetop or in the microwave until the beef reaches 165°F.