A balanced soy, oil, acid, and garlic marinade gives this lean beef cut tender slices and a rich, savory crust.
London broil rewards a little planning. The cut is lean and wide, but it can turn chewy when it’s underseasoned or cooked past the sweet spot. A steady marinade helps on both fronts: it salts the meat, adds aroma, and helps browning.
The best version isn’t fussy. You want salty, tangy, slightly sweet, and full of garlic and pepper. That mix should wake up the surface without drowning the beef. Then you cook it hot, rest it, and slice it thin across the grain.
This recipe works well for a 1 1/2- to 2-pound piece sold as London broil, whether the label points to flank steak or top round. Flank steak likes a shorter soak; top round likes more time.
Why This Cut Likes A Marinade
London broil is known for long muscle fibers and a lean profile. That gives it a deep, beefy taste, but not much room for sloppy technique. A marinade won’t turn it into pot roast-soft meat, yet it does make the bite juicier and the outer layer more flavorful.
Think about the marinade in layers:
- Salt seasons the meat and helps it hold onto moisture.
- Oil carries garlic, herbs, and pepper over the surface.
- Acid brightens the flavor and softens the outer edge.
- A touch of sugar helps the crust brown fast.
- Aromatics like garlic, onion, rosemary, or thyme fill in the gaps.
What you don’t want is a bowl full of acid. Too much lemon juice or vinegar can leave the outside soft and the inside flat. A better plan is balance. Soy sauce gives salt and savoriness, oil rounds out the texture, and a modest amount of acid keeps the whole thing lively.
Ingredient List And Measurements
Use these amounts for 1 1/2 to 2 pounds of beef:
- 1/3 cup soy sauce
- 3 tablespoons olive oil
- 2 tablespoons lemon juice or red wine vinegar
- 1 tablespoon Worcestershire sauce
- 1 tablespoon brown sugar
- 4 garlic cloves, finely minced
- 1 teaspoon black pepper
- 1 teaspoon chopped rosemary or thyme
- 1/2 teaspoon onion powder
Whisk until the sugar melts into the liquid. If you want a glossy finish, scoop out two tablespoons before the raw beef goes in. Brush that clean portion on during the last minute of cooking.
London Broil Marinade Ratios That Work
Ratios matter more than a packed pantry. Once the salty base, fat, acid, and aromatics are in line, you can swap small pieces without losing the plot. Use the table below as your anchor when you want to tune the taste.
| Marinade Part | Amount For 1 1/2 To 2 Pounds | What It Does |
|---|---|---|
| Soy sauce | 1/3 cup | Salts the meat and adds depth |
| Olive oil | 3 tablespoons | Coats the surface and helps browning |
| Lemon juice or red wine vinegar | 2 tablespoons | Lifts flavor and softens the outer layer |
| Worcestershire sauce | 1 tablespoon | Adds tang and extra savoriness |
| Brown sugar | 1 tablespoon | Builds color and balances salt |
| Garlic | 4 cloves | Gives the marinade its backbone |
| Black pepper | 1 teaspoon | Adds bite without stealing the show |
| Rosemary or thyme | 1 teaspoon | Gives the beef a woodsy finish |
| Onion powder | 1/2 teaspoon | Rounds out the savory side |
Marinating Time And Storage
For flank steak, 4 to 8 hours is often enough. For top round, 8 to 12 hours gives the seasoning more reach. Past that point, the gains get smaller. The USDA’s marinating safety notes say meat should stay in the refrigerator while it marinates, and many recipes land in the 6 to 24 hour range. The same page warns that meat left in marinade for more than two days can turn mushy.
Use a zip-top bag, glass dish, or stainless steel container. Flip the meat once or twice if you’re using a dish so both sides stay coated. Don’t reuse raw marinade as a sauce unless it’s boiled first. The cleaner move is to reserve a small batch before the meat goes in. If the beef has already spent a few days in the fridge, keep the soak on the shorter side. The FDA’s refrigerator and freezer storage chart lists fresh steaks and roasts at 3 to 5 days in the fridge.
How To Cook Marinated London Broil
A hot grill, grill pan, or cast-iron skillet all do the job well. You want fast color on the outside and a warm pink center. Pull the meat from the fridge about 20 minutes before it hits the heat so it cooks more evenly.
Pan, Grill, Or Broiler
All three can work. A grill gives smokier edges. A skillet builds a darker crust and makes it easy to spoon on a reserved glaze. A broiler is handy when the weather is rough, but keep the meat close to the heat and watch the color closely.
- Pat the meat dry. Too much wet marinade blocks browning. Leave a thin film, not puddles.
- Heat the pan or grill well. You want that first sizzle right away.
- Cook 4 to 6 minutes per side for a piece around 1 inch thick, then check the center.
- Rest 5 to 10 minutes. The juices settle back into the meat.
- Slice thin across the grain. Turn the meat so the long fibers run left to right, then cut across them.
For whole cuts of beef, the USDA’s safe temperature chart lists 145°F with a 3-minute rest as the food-safety mark. Many cooks stop a little earlier for a rosy center, then let carryover heat finish the job. If you like the meat closer to medium, pull it around 150°F after resting.
The grain matters as much as the thermometer. Even a well-marinated piece can feel tough when it’s sliced with the grain or cut too thick. Thin slices shorten the chew and let the marinade hit every bite.
| Result You Want | Pull From Heat | What You’ll Taste |
|---|---|---|
| Rare center | 125 to 130°F | Soft bite, red center, light chew |
| Medium-rare center | 130 to 135°F | Juicy slices and full beef flavor |
| Medium center | 140 to 145°F | Less juice, firmer chew, still tender if sliced thin |
| Medium-well center | 150°F | More chew, better with extra resting time |
| Dark crust without overcooking | High heat, short cook | Deep browning and a cleaner beef taste |
Common Mistakes That Flatten The Flavor
A muddy marinade is the first trap. Too many bottled add-ins can make the meat taste busy instead of bold. Keep the list tight and let the beef stay in the lead.
Another miss is salting too lightly. London broil is thick enough to mute weak seasoning. If your cut is close to 2 pounds and thick in the center, add a small pinch of kosher salt to the mix.
Then there’s overcooking. This cut doesn’t have much marbling to hide that mistake. Pull it sooner than you think, rest it, and slice it thin.
Leftovers And Make-Ahead Notes
Cooked slices are great tucked into grain bowls, salads, sandwiches, or wraps. Chill them in a shallow container so they cool down fast. Cooked meat dishes usually keep well for 3 to 4 days in the fridge.
If you want to prep ahead, whisk the marinade up to two days early and keep it chilled. You can also freeze the raw beef in the marinade. As it thaws in the fridge, it marinates at the same time, which saves a step on busy nights.
Easy Swaps When The Pantry Is Thin
If you’re short on one ingredient, don’t scrap the whole plan. Use these simple switches and keep the balance close:
- No soy sauce: Use tamari or a mix of Worcestershire and a pinch of salt.
- No lemon or vinegar: Try a splash of orange juice and trim the sugar a bit.
- No fresh garlic: Use 1 teaspoon garlic powder.
- No rosemary or thyme: Italian seasoning works well in a pinch.
- Want heat: Add 1/4 teaspoon red pepper flakes.
The base idea stays the same: salty, oily, tangy, and aromatic, with just enough sweetness to help the crust. Once that balance clicks, the recipe is easy to repeat.
Serve the slices with roasted potatoes, a sharp salad, or rice that can catch the juices. If the meat is thick, slice it on a slight angle for wider pieces. That looks better on the plate and gives each bite more surface seasoning.
References & Sources
- USDA Food Safety and Inspection Service.“Grilling and Food Safety.”Lists refrigerator marinating advice, common marinating windows, and the texture risk after long soaking.
- U.S. Food and Drug Administration.“Refrigerator & Freezer Storage Chart.”Gives fridge storage times for fresh steaks, roasts, and cooked meat dishes.
- USDA Food Safety and Inspection Service.“Safe Minimum Internal Temperature Chart.”Gives the safe internal temperature and rest time for whole cuts of beef.

