How Long to Cook Corned Beef in the CrockPot. Cook in the slow cooker on high for closer to 6 hours. Most recipes recommend you cook the brisket for 4 to 4 1/2 hours on high in the slow cooker. In doing so you'll have nicely cut portions that while tender, simply don't fall apart when stuck with a fork.
ANSWER: They are both beef, but not the same thing. Fresh beef brisket is like a big roast. Corned beef starts out as beef brisket and is brine-cured first. The brine-cure is what makes it corned beef and that curing process is where it gets its color from.