First, it looks like a deflated balloon. Second, when you bite it, it squeaks against your teeth like a rubber toy. Third, your guests start chewing very, very slowly, trying to figure out if they need to spit it out politely. Overcooked brats are the grief of the cookout. Don’t be the cause of that grief.
Also, never, ever microwave a bratwurst. That’s not cooking. That’s a cry for help. You wouldn’t microwave a steak, so don’t microwave a brat. Unless you’re in a dorm room, in which case, God bless you, and please use the “defrost” setting.
So, the final answer is this: 20 to 25 total minutes from fridge to plate, with some kind of pre-cook step. If you boil them first, that time includes the bath. If you don’t, add a few minutes to the grill. But honestly, the real secret to the perfect brat is the company you keep while cooking them. And the mustard. Definitely the mustard.
Now, go forth and grill. Or fry. Or air-fry. Just don’t burn them, and you’ll be a hero in your own backyard.
