NPH insulin has the advantage that it can be mixed with an insulin that has a faster onset to complement its longer lasting action, which is the primary reason NPH remains on the market today, because manufacturers sell a variety of premixed insulin formulations.
Wrap the foil tightly around the brisket to seal in heat and moisture while it cooks. Place the baking dish with the aluminum-wrapped brisket in the oven and bake for around one hour per pound of meat. Increase cooking time to 90 minutes per pound if you are cooking larger cuts of brisket, those weighing 8 to 12 pounds.
In a large flame-proof casserole or Dutch oven, heat the bacon grease over medium heat. Season the beef brisket with salt and pepper. Working in batches to avoid crowding, add the brisket and cook, turning occasionally, until browned on all sides, about 8 minutes. Transfer the brisket to a plate.