Flank Steak
Flank steak is a thin, fibrous cut taken from the abdominal muscles (rectus abdominis) of the steer. It is one of the leanest beef cuts but compensates with concentrated, beefy flavor, and demands grain-direction respect when slicing, because its long fibers turn from tender to inedibly chewy depending on the slice angle.
Flank steak is a thin, fibrous cut taken from the abdominal muscles (rectus abdominis) of the steer. It is one of the leanest beef cuts but compensates with concentrated, beefy flavor, and demands grain-direction respect when slicing, because its long fibers turn from tender to inedibly chewy depending on the slice angle.
Flank steak comes from the flank primal, which sits behind the plate primal on the underside of the steer. The muscle is constantly working as the animal breathes and moves, producing a tight, long-fibered grain visible to the naked eye as parallel lines running across the steak. The fibers run lengthwise, which is what makes slicing direction so important, slice with the grain and the fibers stay long and chewy; slice across the grain and the fibers shorten into bite-sized pieces.
A typical flank steak is 1.5 to 2 lbs (700 to 900 g), about 1 to 1.5 cm thick, and oblong in shape. Its low fat content means it cooks fast and dries out quickly past medium. Flank is the canonical steak for fajitas (US), grilled steak salad, stir-fry, and ropa vieja (Cuba). Argentina prizes the closely related "vacío" cut for asado (grilled over wood); Brazil grills the neighboring "fraldinha" similarly.
Also known as: Flank, Bavette (France, related), Vacío (Argentina), Fraldinha (Brazil, neighboring cut).
What good quality looks like
- Long, thin oval shape, typically 30-40 cm long, 15-20 cm wide, 1-1.5 cm thick
- Visible parallel grain lines running lengthwise, this is the defining anatomical feature
- Deep red lean color, slightly darker than ribeye or strip
- Minimal marbling, flank rarely shows the white flecks visible on premium cuts
- Light external fat trim, usually under 0.5 cm
How to cook it
- High direct heat, 3-4 minutes per side for a 1.5 cm thick steak. Pull at medium-rare (54-58°C / 130-136°F), past medium, flank tightens up dramatically
- Marinate for 2-12 hours, flank is one of the few cuts where marinating genuinely improves the texture (acid breaks down the surface fibers)
- Rest 5 minutes after cooking, then slice thinly across the grain at a 45-degree angle. Slicing with the grain produces inedible chewing
- Best applications: fajitas, steak salad, stir-fry, sliced over rice/grain bowls, anywhere the cut benefits from being eaten in thin pieces rather than as a slab
Frequently asked
Why is slicing direction important for flank?
Flank has long, parallel muscle fibers visible as grain lines running lengthwise. Slicing along (with) the grain leaves the fibers full-length, which chews like rope. Slicing across (against) the grain at a 45-degree angle shortens the fibers into bite-sized pieces, which eats tender. The same flank steak can be either great or inedible depending on slicing direction.
What is the difference between flank and skirt?
Both are thin, fibrous cuts from the underside of the steer, but anatomically distinct. Flank is from the flank primal (rectus abdominis). Skirt is from the plate primal (diaphragm muscle). Skirt is fattier and more flavorful; flank is leaner and beefier. Both must be sliced across the grain.
Is flank the same as bavette or vacío?
Closely related but anatomically distinct. Bavette in France typically refers to what US butchers call "sirloin flap" or "flap meat", a similar thin, grainy cut from the bottom sirloin. Argentine vacío is the cap that sits over the flank, a thicker and slightly fattier cut. All three are grilled across the grain, but the underlying muscles differ.
Should I marinate flank steak?
Yes, flank is one of the few cuts where marinating genuinely improves texture. The acid in a typical marinade (lime juice, soy sauce, vinegar) partially breaks down the surface fibers. 2 hours minimum, 12 hours maximum (longer turns the surface mushy). For dry-rub-only cooking, slice extremely thin to compensate for the lack of fiber breakdown.
How does MeatGrader score flank steak?
MeatGrader scores flank on freshness markers (color, surface integrity), grain quality (clean parallel lines indicate proper handling), and visible marbling (limited but present in the best cuts). Since flank rarely reaches the top of the marbling-driven grade scale, the score is driven more by handling-quality factors than by fat content.