The best way to cook brats, in my humble opinion, is to grill them on a charcoal grill which lends the sausages that awesome smoky flavor that no other cooking method can provide. I like using my trusty Weber Charcoal Grill for cooking fresh sausages like bratwurst as it heats up quickly and is easy to control and clean after cooking. Lately I've also been using my Big Green Egg to grill brats and I love the results.
There are two grilling methods that I like to use, high heat open lid grilling and medium heat closed lid grilling.
High heat open lid grilling
With this method I preheat the grill to about 450F-500F and grill brats over direct high heat. I start with raw bratwurst and grill it, frequently turning to prevent bursting and burning, until the internal temperature reaches the safe level of 160F. This normally takes about 8-10 minutes or so.
I use Mesquite wood, which is very strong and perfect for short duration cooking. The end result is perfectly safe to eat, super juicy inside, beautifully browned and crisped up on the outside sausage. It has a mind-boggling smoky flavor that makes you salivate as soon as it hits your nostrils. As you bite into the sausage it bursts with juices and hits you with intense, deep flavors of spices used to flavor the meat.
Medium heat closed lid grilling
I use this method when I want a more pronounced smoky flavor and less browning, or when I want to deliberately extend grilling time, or when I can't constantly tend to the grill and need to step away for a few minutes. With this method I cook at 300F-350F at the grate level with the lid closed. This grilling method prevents flareups and ensures even cooking without burning. I use the same Mesquite and/or Pecan wood for the smoke. I like to have a really heavy smoke going. Bratwurst reaches 160F in about 15-20 minutes and comes out very juicy and with extraordinary smoky flavor and a nice light brown color from the smoke. Can you see a little bit of a beautiful smoke ring?
Other bratwurst cooking methods
Now, is grilling brats the best cooking method? Is there something better? Is there maybe something that is just as good, but different? Let's experiment and see.
Wisconsin style beer poached brats
After doing some research it appears as though Wisconsin style beer poached brats are super popular. I might be one of very few bratwurst enthusiasts who haven't tried this cooking method. Shame on me! Let me quickly fix that.
So, you drop your brats into beer or a 50/50 mix of beer and water... wait, what? Water? No way, make that all beer. Add butter and onions, boil the brats for 20 minutes, then grill. Hm... wouldn't 20 minutes of boiling over-cook brats? Wouldn't grilling them over-cook them even further and dry them out? Is this really a good way to cook brats? Or is this some sort of safety measure for drunken grilling where you will never have to worry about under-cooking your brats and accidentally making your guests sick? Well, here are my findings. I followed Alton Brown's Beer Brats recipe as it makes the most sense to me.
So, I placed the brats, the onion and the butter in a pan and covered with brown ale. Brought to boil, lowered the heat and simmered for about 7-8 minutes until the brats were fully cooked - 160F internal temperature. Some of the liquid evaporated during cooking so I flipped the brats a couple of times along the way.
I let the brats cool down to about 120F internal temperature as I did not want it to rise past 160F during grilling. I then threw the sausages on a pre-heated grill and grilled over high heat for just a few minutes per side. Checked the internal temperature and it was about 150F after I was done grilling. Perfect!
The sausages had light brown, somewhat pale color after grilling, but did not look unappealing. I placed them into beer/butter mix and brought inside. Took out and immediately sliced. They were juicy but not quite as juicy as the grilled brats. Grilled brats had noticeably stronger and more intense original spice flavor, while beer poached brats' spice flavor tasted somewhat bland and watered down. Beer poached brats, on the other hand, had a very noticeable malty and buttery flavor to them. Not bad at all if that's what you are looking for.
More research revealed that there are actually two distinct Wisconsin style beer brat cooking camps. The first camp does poaching before grilling. The second camp poaches brats after grilling. I don't get it. What's the point? Ah, I see. They argue that poaching brats in beer before grilling does very little to flavor the sausage. But putting grilled brats into beer/butter/onion mixture flavors them, akin to putting a BBQ sauce on a rack of ribs. OK... If the brats you use are lacking in flavor or if you want to impart some beer flavor, this sounds like a workable solution. However, as my experiment confirmed, poaching brats in beer does impart strong beer flavor on the sausages, so you will be better off using Alton Brown's beer brat recipe for more malty flavor. Still, grilling then poaching seemed like best of both worlds if you are after that malty flavor. I would make a beer/butter/onion reduction before throwing in brats. That way it be used like a sauce, which I personally would prefer.
Bursts and prickles
I've seen many recipes advising prickling brats with a fork prior to cooking to prevent them from bursting during cooking. Do it only if you want your brats dry with most of the juices run off during cooking.
Sausages burst mainly due to cooking them over too high a heat, as was found by Serious Eats in their Best Way to Grill Sausages article. Let me clarify, cooking brats over high heat without frequently turning them will result in burst casings. Alternatively, cook them over moderate heat, with the lid closed most of the time and you will get no burst sausages.
To me, the best way to cook brats is one where I get the best possible product in the end. In my case it is a perfectly cooked, safe to eat, well-seasoned, flavorful, nicely browned, not burnt, juicy and smoky brat. I get that from grilling my homemade brats over direct heat on a charcoal grill. I can't think of a better way to cook bratwurst.
I've tried the Wisconsin style cooked brats, poached before grilling and grilled before poaching, but was not overly impressed. They are good, but just not my cup of tea. I did not get the same smoky flavor as I do with the grilled brats. Nor did I get the same browning and caramelization. I felt that beautiful sausage flavors were muted by beer and onion flavors, and the malty flavor was great, but dominating.
But that's me. It may be completely different for you. Try different methods and pick the one that works best for you. You'll never know unless you try like I did.