Lazy Day Beef Brisket on BigOven: Marinate for up to 48 hours in the refrigerator, and then bake it in the oven. It's as easy as that to have tender, flavorful brisket. Leftovers can be frozen for chopped beef sandwiches. This marinade recipe will work, without doubling it, for up to a 10 pound brisket. I just did a five pound because my family is small.