Johnsonville suggests cooking its brats in a skillet over medium-high heat until browned, which takes about five minutes. Turn the links often. Reduce the heat to medium-low, add water to the skillet, and simmer for 12 minutes or until cooked through. Grilling or broiling the brats are other options.
To grill Johnsonville brats, preheat the grill to medium-low. When grilling over charcoal, heat the charcoal until a layer of white ash forms before placing the brats on the grill. Turn the brats often while grilling. Cover the brats, and grill them for 15 to 20 minutes more until thoroughly cooked and browned. Do not poke the brats' casings with a fork, since doing so releases the juices that give the sausage its flavor.
BBQ University says the key to perfectly cooked brats is to cook them slowly over a moderate flame until the internal temperature reaches 170 degrees, which takes around 25 minutes. Cook them either directly on the grill, or opt to cook them on the unlit portion of the grill to reduce the chance of burning the brats.
Grilling with a charcoal grill gives the brats a smoky flavor that some people prefer. Enhance the brats' flavor by partially poaching the brats in beer or wine before grilling.