Quick Recipe Version (TL;DR)
Quick Ingredients
- 6 bratwurst links (about 1 1/2 lb / 680 g)
- 2 large yellow onions, thinly sliced (about 1 lb / 450 g)
- 2 tbsp (28 g) unsalted butter
- 1 tbsp (15 ml) olive oil
- 2 bottles lager or pilsner beer (24 fl oz / 710 ml), divided
- 1 tsp kosher salt, plus more to taste
- 1/2 tsp freshly ground black pepper
- 6 brat buns (or sturdy hot dog buns), split
- Spicy brown mustard, for serving (about 1/2 cup)
Do This
- 1. Preheat grill to medium-high (about 450°F / 232°C).
- 2. Caramelize onions in butter + oil over medium-low, 20 minutes.
- 3. Add 12 fl oz (355 ml) beer; add brats; gently simmer 10 minutes.
- 4. Grill brats 6–10 minutes, turning, to 160°F (71°C) internal.
- 5. Keep cooking onions in the beer pan 5–10 minutes until jammy and glossy; season.
- 6. Toast buns on the grill 30–60 seconds.
- 7. Build: bun + mustard + brat + big heap of beer-caramelized onions.
Why You’ll Love This Recipe
- Peak brat texture: A quick beer simmer keeps them juicy, then the grill adds char and snap.
- Onions do double duty: Slow-cooked for sweetness, then enriched with beer into a glossy topping.
- Big flavor, simple steps: Just a skillet and a grill (or grill pan) for classic cookout results.
- Easy to scale: Make 6 or make 12—same method, just a bigger pan.
Grocery List
- Produce: 2 large yellow onions
- Dairy: unsalted butter
- Meat: 6 bratwurst links
- Pantry: olive oil, kosher salt, black pepper, spicy brown mustard, 6 brat buns, 2 bottles lager or pilsner beer
Full Ingredients
For the beer-caramelized onions
- 2 large yellow onions, thinly sliced (about 1 lb / 450 g)
- 2 tbsp (28 g) unsalted butter
- 1 tbsp (15 ml) olive oil
- 1 tsp kosher salt, plus more to taste
- 1/2 tsp freshly ground black pepper
- 1 bottle beer (12 fl oz / 355 ml), lager or pilsner (for the pan)
For simmering and grilling
- 6 bratwurst links (about 1 1/2 lb / 680 g)
- 1 bottle beer (12 fl oz / 355 ml), lager or pilsner (for simmering)
To serve
- 6 brat buns (or sturdy hot dog buns), split
- Spicy brown mustard (about 1/2 cup), or to taste
Optional (but great)
- Sauerkraut, drained
- Dill pickle chips
- Pickled jalapeños
Step-by-Step Instructions
Step 1: Preheat the grill and set up your cooking station
Preheat a gas grill to medium-high (about 450°F / 232°C). If using charcoal, set up a two-zone fire so you have a hotter side for searing and a slightly cooler side to finish.
Set a large skillet (cast iron is ideal) on the stovetop near your grill tools. Have an instant-read thermometer ready; brats are best when cooked through but still juicy.
Step 2: Start caramelizing the onions
In a large skillet over medium-low heat, melt 2 tbsp (28 g) butter with 1 tbsp (15 ml) olive oil. Add the sliced onions and 1 tsp kosher salt.
Cook, stirring every few minutes, for 20 minutes, keeping the heat moderate so the onions soften and turn deeply golden without burning. If you notice fast browning, reduce the heat slightly and stir more often.
Step 3: Add beer and briefly simmer the brats with the onions
Pour 1 bottle beer (12 fl oz / 355 ml) into the skillet with the onions. Raise heat to bring it to a gentle simmer, then reduce as needed to keep it around 185–195°F (85–90°C) (small bubbles, not a rolling boil).
Nestle the brats into the onion-beer mixture. Simmer for 10 minutes, turning once halfway through. This step lightly cooks the brats through the center and infuses them with beer-onion flavor, so they finish quickly on the grill without drying out.
Step 4: Move brats to the grill for char and snap
Using tongs, transfer the brats from the skillet to the preheated grill. Grill over medium-high heat (about 450°F / 232°C) for 6–10 minutes, turning every 1–2 minutes, until the casings are browned and lightly blistered in spots.
Check the thickest brat with an instant-read thermometer; grill until it reaches an internal temperature of 160°F (71°C).
Step 5: Reduce the onions until glossy and jammy
While the brats grill, keep the skillet on the stovetop over medium to medium-low heat. Let the onion-beer mixture cook down for 5–10 minutes, stirring often, until the beer reduces and the onions look shiny, deeply golden, and spoonable.
Season to taste with additional salt and 1/2 tsp black pepper (or more if you like it peppery). If the onions start to look dry before they’re as soft as you want, add a small splash of the remaining beer (1–2 tbsp at a time) to loosen.
Step 6: Toast the buns
Place the split buns cut-side down on the grill for 30–60 seconds, just until lightly toasted. This helps them hold up to the juicy brat and the heap of onions.
Step 7: Assemble and serve
Spread spicy brown mustard inside each bun. Add a grilled brat, then pile on a generous mound of beer-caramelized onions.
Serve immediately while the brats are hot and snappy and the onions are warm and glossy.
Pro Tips
- Don’t boil the brats: Keep the simmer gentle (about 185–195°F / 85–90°C). A hard boil can split casings and push out juices.
- Go for jammy onions: The best topping happens when the beer reduces down and clings to the onions. If it’s watery, keep reducing; if it’s too thick, splash in a tablespoon or two of beer.
- Char in stages: If your brats are browning too fast, move them to a slightly cooler zone of the grill and finish to 160°F / 71°C.
- Choose the right beer: A lager or pilsner is balanced and classic. Very bitter IPAs can make the onions taste harsh.
- Slice onions evenly: Thin, uniform slices caramelize at the same rate and build a more cohesive topping.
Variations
- Brat bar style: Add sauerkraut, pickle chips, and extra mustard. Serve onions on the side so everyone can pile on their own.
- Cheddar brats: Use cheddar-filled bratwurst and swap spicy brown mustard for Dijon or whole-grain mustard.
- Spicy onions: Add 1/2 tsp crushed red pepper flakes to the onions for the last 2 minutes of cooking, then finish with mustard.
Storage & Make-Ahead
Make-ahead: The beer-caramelized onions can be made up to 3 days ahead. Cool completely, then refrigerate in an airtight container. Rewarm in a skillet over medium-low heat with 1–2 tbsp water or beer to loosen.
Leftovers: Store cooked brats and onions separately (or together) in airtight containers in the refrigerator for up to 4 days.
Reheating: Warm brats gently in a covered skillet with a splash of water or beer over medium-low heat until hot (or reheat on a grill over medium heat). Rewarm onions in a skillet until steaming.
Nutrition (per serving)
Approximate, for 1 brat in a bun with onions and mustard (without optional toppings): 520 calories; 29 g protein; 35 g carbohydrates; 28 g fat; 9 g saturated fat; 3 g fiber; 9 g sugars; 1180 mg sodium.
