Reheat a brisket so it stays moist and tender, just as when it first came out of the oven or smoker. Reserving the juices when you cook it makes reheating easier, but you can use other liquids, if necessary. Chilled brisket is actually easier to cut so the reheating stage is the ideal time to cut it into slices. After you pull it out of the oven, when provided enough moisture and the appropriate cooking time, it should look and taste just as good as when it was fresh.
Preheat the oven to 350 degrees Fahrenheit.
Remove the brisket from the refrigerator.
Skim off any fat from the brisket with a spoon.
Place the brisket on a cutting board.
Slice off any excess pieces of fat with a clean, sharp knife. Cut the meat into thin slices, going against the grain.
Place the brisket slices in a baking pan with any juices reserved from when you cooked the meat.
Cover the baking pan tightly with foil.
Place the pan in the preheated oven and cook for about 30 minutes, or until the meat is heated throughout and it reaches 165 degrees on a meat thermometer.