How long to cook brisket per pound in oven?

Brisket is best if it is cooked at a lower temperature. This takes longer but the result is a tender product. I like to use about a 300 degree oven. A smaller roast (4 or 5 pound) will take 3 to 5 hours. We usually buy a larger roast (15 pounds) and put it in the oven late at night at about 275 and let it bake 8 to 10 hours.