Prepare the grill by positioning firebricks and preheating to high.

Combine beer bath ingredients in a baking dish.

Place the dish on the bricks, cover, and preheat for 45 minutes.

Add bratwurst to the beer bath.

Cover and cook for 20 minutes, flipping halfway.

Pour canola oil into another baking dish.

Remove bratwurst from the bath, roll in oil, and place on the grill.

Turn to brown and caramelize on all sides, about 2 minutes per side.

Serve immediately or hold in beer bath on low heat for up to 1 hour.

Check beer bath temperature, maintaining at 140 degrees F.

Serve brats on soft rolls with onions, sauerkraut, and mustard.

For grilled sweet onions, cut onions into thin slices.

Place a cast-iron griddle on the grill and preheat.

Toss onions with olive oil, thyme, sugar, salt, and pepper.

Pour remaining olive oil on griddle and heat.

Spread onions on griddle and decrease heat to medium.

Cover and cook for 10 minutes without stirring.

Move onions to one side of the griddle.

Melt butter, add garlic, and stir.

Cook until fragrant, about 1 minute.

Stir onions and garlic together, and cook until onions are tender, about 3 minutes.

Pour vinegar onto the griddle and mix into the onions.

Serve directly from the grill or transfer to a bowl.