Grilling a london broil delivers bold, beefy flavor, but timing is critical to avoid a tough, uneven result. Understanding how long to cook london broil on the grill depends on thickness, heat level, and your preferred doneness, so a precise plan matters.
This guide breaks down grill times, temperature targets, and practical tips so you can serve a juicy, sliceable london broil every time. Use the timings and temperatures below as your baseline, then adjust for your grill and cut.
| Cut Thickness | Grill Temperature | Cook Time per Side | Target Internal Temp |
|---|---|---|---|
| 1 inch (2.5 cm) | Medium-high (375–400°F / 190–205°C) | 4–5 minutes | 130–135°F (54–57°C) for medium-rare |
| 1.5 inches (3.8 cm) | Medium-high (375–400°F / 190–205°C) | 5–7 minutes | 140°F (60°C) for medium |
| 2 inches (5 cm) | Medium (325–375°F / 165–190°C), finish with indirect | 6–8 minutes per side | 145–150°F (63–66°C) for medium-well |
| Over 2 inches (5+ cm) | Indirect zone setup around 300–325°F (150–165°C) | 8–12 minutes per side, then rest | 150–155°F (66–68°C) to stay juicy |
Preparing the London Broil for the Grill
Proper prep sets the stage for even cooking and deep flavor. A trimmed, seasoned london broil sears well and avoids flare-ups from excess fat.
Trimming and Tenderizing
Remove large pockets of fat and, if desired, lightly pound or score the surface to promote even cooking and faster heat penetration without turning the meat mushy.
Seasoning and Marinating Options
A simple rub of salt, pepper, garlic powder, and paprika works well, while a marinade with acid, oil, and herbs can add flavor and slight tenderizing. Pat the surface dry before grilling so the sear is clean.
Direct vs Indirect Grilling Techniques
Choosing between direct and indirect heat shapes how long to cook london broil on the grill and how even the results are.
When to Use Direct Heat
Use direct, high heat for thin cuts and developing crust. Sear each side for the times noted in the table, then move to indirect if the center needs finishing.
When to Use Indirect Heat
For thicker cuts, set up an indirect zone, cook with the lid closed until near target temperature, then briefly sear for flavor and texture.
Temperature and Timing Targets
Precision matters more than guesswork when determining how long to cook london broil on the grill. Rely on a reliable instant-read thermometer for accuracy and consistency.
Temperature Guide by Doneness
Plan for 130–135°F (54–57°C) for medium-rare, 140°F (60°C) for medium, 145–150°F (63–66°C) for medium-well, and 155°F (68°C) for well done to balance safety and juiciness.
Resting and Slicing for Best Results
Resting is not optional; it lets juices redistribute so every slice stays moist and flavorful instead of pooling on the plate. p>
How Long to Rest
Let the london broil rest for at least 5–10 minutes under a loose foil tent, then slice thinly against the grain for a tender bite.
Serving Suggestions
Pair with bright salads, roasted vegetables, or grilled stone fruit, and finish with a simple sauce to highlight the beefy character of the meat.
Key Takeaways for Perfectly Grilled London Broil
- Match thickness to technique; thin cuts suit direct sear, thick cuts benefit from indirect finishing.
- Use time and temperature targets instead of guesswork to hit your desired doneness.
- Always rest the meat 5–10 minutes and slice against the grain.
- Trim excess fat, season or marinate in advance, and dry the surface for best sear.
- Plan for slight time increases for frozen or very thick cuts, and manage flare-ups with indirect zones.
FAQ
Reader questions
How do I know when the london broil is done without a thermometer?
Press the center gently; medium-rare feels like the fleshy part of your thumb when you touch thumb to index finger, with some give but not mushiness. For medium, the resistance increases slightly, and for well done, it feels quite firm.
Can I grill a frozen london broil?
Yes, but add roughly 30–50 percent more cook time and use indirect heat first, then sear. Keep the cut well seasoned and patted dry once thawed enough to sear safely.
Should I close the lid during grilling?
Keep the lid closed during most indirect cooking to retain heat and promote even doneness. Open it only for quick checks, flare-up management, or final searing.
How long can I store cooked london broil in the fridge?
Refrigerate cooked london broil in an airtight container for 3–4 days. Reheat gently in a skillet or low oven, adding a splash of broth to retain juiciness.