You can make homemade bratwurst at home.
In a small bowl, combine spices. Sprinkle mixture evenly over meat; mix thoroughly. With the coarse blade of a food grinder, grind the meat with the spice mixture until well mixed. Use a medium stuffer for casings. Run cool water through casings, soak in water 2 hours or overnight in the refrigerator.
Attach sausage stuffer attachment to an electric mixer or food grinder. Using a 3 to 4-foot piece of the casing at a time, slip one end and then the remaining length of casing onto the medium or small stuffer tube. Using coast blade of grinder force sausage mixture through the tube till even with the tube opening. Pull off two inches of the casing and tie a knot. Fill the casing firm, but not too full, twisting casing when the links are 4 to 5 inches long. If desired, tie string at the twist. Wrap and chill at once. Cook soon, or freeze, for later use.