This guide draws on three grilled flank steak methods that don’t quite agree with each other: Weber’s Balsamic-Marinated Flank Steak Sandwiches recipe, Meathead Goldwyn’s Crusty Grilled Flank Steak recipe at AmazingRibs.com, and America’s Test Kitchen’s Grilled Flank Steak with Garlic-Shallot-Rosemary Marinade. Safe handling numbers come from the USDA Food Safety and Inspection Service.
Marinade, Paste, or Just Salt?
The three sources don’t even agree on whether flank steak needs a liquid marinade at all. Weber’s version is the classic approach: a marinade of balsamic vinegar, extra-virgin olive oil, Worcestershire sauce, Dijon mustard and minced garlic, with the steak refrigerated in a sealed bag for at least 4 hours or overnight, turning occasionally.
ATK takes a different route. Instead of a liquid marinade, its test cooks blend olive oil, garlic, shallot and rosemary into a paste, then use a technique they call “marinating”: prick the steak about 20 times per side with a dinner fork, rub it first with salt and then with the paste, and refrigerate anywhere from 1 to 24 hours. The paste is wiped off before the steak hits the grill.
AmazingRibs skips a marinade entirely. Meathead’s method is a dry brine: an hour or two before cooking, the steak’s surface is moistened, salted, and left uncovered in the fridge so the salt can work its way into the meat. He then coats the steak lightly with oil right before grilling, purely to help it brown and keep it from sticking.
Setting Up for High Heat
Because flank steak is thin, all three sources push for aggressive heat. AmazingRibs recommends a two-zone charcoal fire with the coals raised to about 2 inches below the cooking grate — on a Weber Kettle, that means bricks under the charcoal grate — specifically to get hotter than a standard setup allows, aiming for a dark brown, almost-charred crust. ATK builds a two-level charcoal fire and grills the steak directly over the coals. Weber’s approach is more moderate: direct medium heat at 350° to 400°F.
Both AmazingRibs and ATK also flag flank steak’s uneven thickness — one end is typically noticeably thicker than the other. AmazingRibs’ fix is to cut the steak in half if one end is more than a ¼ inch thicker, and start the thick half on the grill about 2 minutes ahead of the thin half.
Grilling Times: Where the Numbers Diverge
Weber’s timing is the longest of the three: 8 to 12 minutes total for medium-rare over direct medium heat, turning once. AmazingRibs’ hotter fire cuts that down substantially — about 4 minutes on the first side until it’s visibly dark brown, then about 3 minutes on the second side, with exact timing dependent on the grill. ATK lands in between: 4 to 6 minutes on the first side and 3 to 4 minutes on the second, checking doneness with a paring knife cut into the thickest part before pulling the steak.
Safe Internal Temperature
None of the three recipes builds a specific target temperature into their instructions the way a thermometer-driven method would, but USDA guidance is the baseline food-safety number to check against: whole beef cuts, including steaks, should reach a minimum internal temperature of 145°F (62.8°C), followed by a rest of at least 3 minutes, according to the USDA Food Safety and Inspection Service’s Safe Minimum Internal Temperature Chart. Ground beef needs a higher 160°F. Checking with an instant-read thermometer in the thickest part of the steak is a more reliable way to confirm doneness than any of the time estimates above, since grill hardware and steak thickness both change the math.
Resting and Slicing Against the Grain
All three sources agree completely on what happens after the steak comes off the grill, even though they disagree on how it got there. Weber has the cook rest the steak 3 to 5 minutes before cutting it across the grain into thin slices. AmazingRibs is the most specific about the cut: hold the blade at an angle and slice 1/8-inch pieces across the grain, noting that the very first cut will look slightly overcooked but the center slices will be right. ATK’s instructions make the same point from the food-safety side — the steak needs to rest before slicing “if the steak is to retain its juices,” since cutting into it too soon lets the juices run out rather than redistribute.
Flank steak’s grain runs in one clear direction along the length of the muscle, and cutting parallel to it — rather than across it — is what makes the difference between tender bites and a genuinely chewy result, regardless of which marinade or heat method got the steak to the cutting board.
Keep reading
- How to Grill Skirt Steak: Inside vs Outside, Heat, Timing
- How to Grill Boneless Chicken Breasts Without Drying Them
- Grilling Flat Iron Steak: Weber and ATK’s Methods
- How to Grill Pork Chops: Thickness, Brine and 145°F
Sources
- Balsamic-Marinated Flank Steak Sandwiches with Peppers and Onions — Weber official recipe library
- Grilled Flank Steak Recipe — Meathead’s AmazingRibs.com
- Grilled Flank Steak with Garlic-Shallot-Rosemary Marinade — America’s Test Kitchen
- Safe Minimum Internal Temperature Chart — USDA Food Safety and Inspection Service