Rule number 1 : The Bratwurst is actually not called a Bratwurst but a Brät -Wurst. It got its name from what was put inside the intestines: a roast made of ground meat with spices and salt.
The underlying concept is: By filling it in a protective cover such as casing or casing, the sausage meat can be cooked more gently and gently. This differs from the meatball or other fried or grilled minced meat preparations. Basically, the sausage meat is cooked almost "sous . . .