In a medium bowl, mix together the water, Worcestershire sauce, vinegar, bouillon granules, dry mustard, chili powder, red pepper and garlic. Reserve 1/2 cup liquid for the BBQ sauce; set aside and store in the fridge until later. Place meat in a 4 quart crock pot. Pour remaining liquid over brisket.
Cover the crock pot and cook on low for 10 to 12 hours or on high for 5 to 6 hours.
Near the end of the cooking time, make the BBQ sauce. In a small saucepan, combine the 1/2 cup reserved liquid, ketchup, brown sugar and butter. Cook until heated through. Remove from heat and whisk until sauce thickens and becomes smooth. Serve with the cooked brisket.
Source: New Better Homes and Gardens Cook Book