Brats and Other Sausages
One of the common "issues" with cooking brats and sausages on the grill is that they break and/or split. More often than not, this is because they are placed under an extremely high heat, and the high temps cause the casing to contract to quickly and rip open. Some people are completely ok with the ripping, and if you're from the East Coast, you're well aware of "rippers" or deep-fried cased meats that "rip" open and are crispy and charred and delicious. For those that are not into the ripped casing, what you want to do is cook your meats on a low, indirect heat. A medium heat is likely fine as well, but you'll need to play around with your threshold based on the cased products you have. What you're looking for is a fully cooked-through brat that hasn't ripped. The cook time obviously varies by temperature of cooking environment, but indirect heat will give you a nice crisp, snappy casing and sausage.
Cook and Split
Growing up on the East Coast, we cooked our sausages a bit different than is typical here in Michigan, and quite frankly, most of the country. What we ended up doing was cooking our sausages half way through and then splitting them, or butterflying them, down the middle. From here you had a partially cooked and bound sausage that had these "rough" edges that were primed to take on a beautiful crispy char. So, here's how we do it. We cook the sausage over high heat for about 2 - 3 minutes per side. This allows the meat to set and bind up into something you can split without it becoming a Sloppy Joe-style mess. Once you've cooked both sides, remove from heat and slice down the middle, taking care not to slice through the other side of the casing, so that it butterflies out. At this point, flip and cook through over high heat on the exposed, split sides. This will yield a crispy and charred, albeit well done, brat that will be reminiscent of the East Coast boardwalk sausages.
Low Temp and Clinching
Low temp again. Yes, as you might guess, it's the same method as mentioned above and the benefits are exactly the same. By low temp cooking the sausages, you're cooking through, evenly, the cased meat, ensuring that the end product is an even doneness. By starting the cooking process this way, it opens up a couple of different options for finishing the cooking, one of which is any high heat method. Because you've cooked, and set, the sausages during low temp cooking, you can now sear and char over a very high heat without risk of the casing breaking into an unrecoverable mess. My preferred method of post-low temp cooking is clinching. As mentioned above, you'll be cooking directly on the cherry coals and utilizing the high heat to sear in flavor via char and smoke. With sausages, this is no different. Over hot, cherry, coals, place the low temp cooked sausage onto the coals and sear, hard, for one to one and half minutes per side. Remove from the coals, let rest and enjoy the most amazing sausage you've ever had.
All in all, cooking on the grill isn't rocket science. It is the most primitive and simplistic, of cooking methods. Wood/Coals, fire and food. It's been around since the dawn of time and our job as cooks is to leverage its inherent possibilities. Smoke, char and ash are all the elements that come to the table when cooking over fire. Hopefully we've given you some tips to take the ordinary into the extraordinary. Impress your friends with your new techniques and change the perception of what a "simple burger" or "Brat on a roll" can be.