In a large bowl, mix together the ground beef, pork sausage, mustard seed, liquid smoke, Worcestershire sauce, garlic powder, curing salt, black pepper, caraway seed, cayenne pepper, paprika, chili powder and red pepper flakes. Cover, and refrigerate overnight.
For the next three days, knead the meat for 5 minutes, then return to the refrigerator. On the fourth day, knead, then form into 6 equal logs. Wrap each log in aluminum foil, and poke a few holes in the foil.
Preheat the oven to 200 degrees F (95 degrees C). Place the logs onto a broiler pan to catch the grease. Bake for 6 hours in the preheated oven. Turn off the oven, and leave the logs in for another 3 hours after baking. Refrigerate until chilled, then slice and serve.
