Slicing Flank Steak Against the Grain: Does It Matter?

Slicing flank steak against the grain is the biggest single thing you do to it, bigger than the marinade and bigger than the sear. The fibres run the long way down the steak, the knife has to cross them at 90 degrees, and the slices want to be about 1/4 in thick. Miss that and a steak cooked perfectly to medium-rare still eats like a belt.

The part the recipes leave out is that you have to read the grain while the meat is raw. Once it is seared and glistening, the lines are gone. I slice on a Houseland stainless steel cutting board, 304 food-grade steel and non-porous, so raw-beef juice sits on top rather than soaking in, and I sharpen before the steak goes near heat, because that same steel is hard on an edge.

Which way does the grain run on a raw flank steak?

The long way down the steak, usually on a slight diagonal rather than square to the edge. Flank comes from the abdominal muscles, just behind the plate and in front of the rear quarter, and the plain description of the cut is blunt about the consequence: it is "long, flat, and has a significant grain that is typically sliced thin to minimize its chewiness".

Lay the raw steak flat under a bright light and look across it at a low angle, not down at it. You want the fine parallel lines that look like brushed timber. They run nearly parallel to the long edge at the thick end and fan a few degrees at the tapered tail, so the two ends do not want the same knife angle.

Mark the direction before you cook, because a browned surface hides the grain completely. It takes four seconds: nick each end about 1/2 in deep with the knife tip, running the nick the way you intend to slice. The nick survives a hot grill. Your memory of which way the lines ran does not.

Does slicing flank steak against the grain really change anything?

It changes the bite by a factor of four or more on the same piece of meat. America's Test Kitchen put slices of one cooked steak under a force gauge and needed 383 grams of force to bite through a slice cut across the fibres, against 1,729 grams for a slice cut along them. Same steak, same doneness, four and a half times the work for your jaw. It is cited by name because the page carrying it would not open.

The mechanism is geometry, not chemistry. Muscle runs in long bundles of fibre; cut along them and every bundle in the slice is 5 in of intact rope your teeth have to shear. Cut across at 1/4 in and the longest fibre on the plate is 1/4 in.

Meat science measures this with the Warner-Bratzler Shear Force test and the Slice Shear Force test, and the standing summary is that tenderness "depends on a number of factors including the meat grain, the amount of connective tissue, and the amount of fat". Grain is first on that list. Ignore the pair of shear-force figures that circulate on recipe pages as proof of it: they trace to no published study, and a number without a method behind it is decoration.

Is a bavette the same cut as a flank steak?

No, and the mix-up is one reason a single slicing angle gets half a steak wrong. Bavette is the French name for flap steak, cut from the obliquus internus abdominis of the bottom sirloin, and the term is "often mistranslated as 'flank steak'". Flap is the cut whose coarse grain genuinely swings across the width, so if the label says bavette, check both ends first.

Skirt is the third confusion in the same corner of the animal: inside skirt "is often confused with the flank steak", shares its cooking properties, and is also sliced against the grain to maximize tenderness. Whichever of the three is on the board tonight, only the geometry moves.

How do you cook and slice a flank steak so it stays tender?

Eight steps, and the two that decide the outcome sit outside the cooking altogether.

1. Mark the grain while the steak is raw, with a nick at each end running the way you will slice. This step separates a good result from a coin flip.
2. Dry the surface hard with paper towel, then salt. A wet flank steams, and it has almost no fat to carry a crust it never built.
3. High heat, short time: a 3/4 in flank wants roughly 4 minutes a side over a hot fire. The minutes are a guess; the temperature is the fact.
4. Pull it at 130F (54C) for medium-rare on the plate. The published bands run rare 125 to 130F (52 to 55C), medium rare up to 140F (60C), medium 140 to 150F (60 to 65C).
5. Allow for carryover, but less of it than you think. The residual rise runs between 5 and 25 degrees Fahrenheit (3 to 14C), and bigger, denser pieces rise most, having a lower surface-area-to-volume ratio. A thin flank sits at the bottom of that band: pull 5F under target, not 20F.
6. Know the regulator's number and choose deliberately. Illinois Extension puts whole cuts of beef at 145F with a rest of at least 3 minutes, ground meat at 160F, poultry at 165F, fish at 145F. Medium-rare is defensible on a whole muscle because contamination sits on the outside and the sear runs far hotter than 145F. It stops being defensible if the butcher blade-tenderised the steak, carrying surface bacteria inwards, or if you are feeding someone pregnant, elderly or immune-compromised. Then cook to 145F and give it the 3 minutes.
7. Rest it 5 to 10 minutes. Resting eases carving, firms the structure against the knife, and holds water in.
8. Slice thin and across the fibres, blade tipped about 45 degrees to the board. Find your nick, set the knife square to the lines, cut in one long draw rather than sawing, and re-read the grain at the tail where it fans.

What do you actually need for this?

A thermometer and a sharp knife outrank every pan and every board on this dish, and one popular gadget actively hurts.

• Required - an instant-read thermometer, because the gap between 130F and 150F is the gap between a steak worth slicing and one nothing can save; a blade long enough to cross a 5 in wide steak in one draw, since sawing tears the fibres it should cut; and a surface that will not shift while you push.
• Optional - a sharpener, used the morning you cook rather than the week after. It buys a clean shear instead of a crush; without one you still get dinner, just with ragged slice faces that shed juice. Results fade fast on a hard surface, which is why sharpener results only last one meal, and the machine has to match your blades, so check which knives a pull-through is built for.
• Not needed - the blade tenderiser, the jaccard, the roller of little needles. It drives outside bacteria into the middle of the muscle, which is the case where 145F stops being optional, and it does nothing for chew that a 1/4 in slice does not do better.

Does a steel cutting board help or hurt when you're slicing steak?

Both, and the honest order is hurt first. Dean O. Cliver's Food Safety Laboratory at UC Davis, the lab that studied cutting surfaces properly, wrote that glass and stainless steel work surfaces are "quite destructive of the sharp cutting edges of knives, and therefore introduce another class of hazard to the kitchen". On a dish whose whole outcome rests on the knife, that trade deserves saying out loud.

Scale explains why it bites here. An extremely sharp edge is under a micron wide, a razor averages about 0.1 microns, and an edge is effectively dull by around 10 microns. A few passes onto a hard surface move an edge along that scale, which is why sharpening belongs before the steak, not after the washing up.

What steel is good at is the raw half of the job. The Houseland board is a single piece of stamped, uncoated 304 food-grade steel, non-porous, so raw-beef juice and odour sit on top instead of soaking in, and it is dishwasher safe with nothing to oil, season or soak. Its juice groove runs the full perimeter of the grooved side, which matters on a flank because thin slices shed a surprising amount. The alloy also holds oxidation resistance in intermittent service to 870C, so a steak straight off the grill is a non-event. Houseland lists two sizes, 12 x 8 in (30.5 x 20.3 cm) and 15.4 x 11 in (39 x 28 cm), and a whole flank wants the larger - the reasoning is in this size comparison. Steel is slick under a wet steak, so read how to chop on a slick steel board first.

From the shop

Stainless Steel Cutting Board, 304 Food-Grade, Double-Sided with Juice Groove

Double-sided 304 food-grade stainless steel: juice groove around the full perimeter on one side, flat prep face on the other. Dishwasher safe, nothing to oil or season. 12 x 8 in (30.5 x 20.3 cm) or 15.4 x 11 in (39 x 28 cm).

View the 304 stainless steel board — 2 sizes & current price

Your flank steak is still chewy - what went wrong?

Four culprits, in the order they usually happen.

• The grain turned and the angle did not. The thick end came out fine and the tail chewed. Re-read the lines halfway down; two angles on one steak is normal, not sloppy.
• The slices were 1/2 in thick instead of 1/4 in. Double the thickness and you double the intact fibre in every mouthful, which undoes the cross-cut.
• It went past 150F. Medium starts at 140F and a flank has little fat to cover the loss, so the window between right and ruined is narrower than on a ribeye.
• It was carved straight off the heat. Without 5 minutes of rest the structure is slack, the knife pushes rather than cuts, and the juice ends up in the groove.

Not on the list: the marinade. Acid seasons the outside and does little to fibre length, so no soak rescues a steak sliced the wrong way.

What I'd do

Nick both ends of the raw steak the way I mean to slice it, sharpen while the grill heats, cook hard and fast, pull at 130F, rest 8 minutes, then cut 1/4 in slices across the fibres at 45 degrees, resetting the angle at the tail. The thermometer and the nick do most of the work.

The board that catches the juice sits in the kitchen and home collection. Buy the sharpener first, though: on this dish the edge earns its keep before anything else does.

Shop kitchen & home from Houseland

-14%Titanium Frying Pan, Uncoated, Induction Safe, with Tempered Glass Lidfrom $119.99$139.99Stainless Steel Finger Hand Protector, Knife Guardfrom $29.99-14%Kitchen Knife Sharpener, 3-Stage and 4-Stage Manual Pull-Throughfrom $29.99$34.99-40%Coconut Bowl Set of 4 with Wooden Spoons, Coconut Shell Bowls for Acai and Pokefrom $67.49$112.49-17%Coconut Wax Candle in a Coconut Shell, Cotton Wick, Hand-Poured, 4 Scentsfrom $49.99$59.99Ceramic Salt Cellar with Spoon, Speckled Bamboo-Lid Spice Jar Set for Kitchen Counterfrom $39.99

See all kitchen & home →