Flank steak is an odd cut of beef. I don’t care what anyone says. It’s fairly lean, relatively affordable, and its texture has a coarse, ropy look. At first glance you might say, “No thanks, I’ll take the New York Strip!”

But flank steak, also known as London Broil, is a delightful cut of meat! It cooks quickly, takes marinades beautifully, and is easy to serve to a crowd! You’ve probably eaten it before and never realized it because it’s the cut most often used for fajitas.

THE SECRET TO TENDER, JUICY FLANK STEAK

You really need a three-pronged approach.

1. Use acid in your marinade. It helps to break down proteins in the meat, making it more tender.
2. Flank steak is lean. Like most lean meats you need to cook it fast and hot!
3. Finally, slice it thin across the grain of meat, which shortens the muscle fibers, creating a more tender bite of meat.

That’s it!

WHAT MAKES A GOOD FLANK STEAK MARINADE?

Flank steak needs a little acid to help tenderize the fibrous muscle and provide flavor. Do this, and you will have tender, succulent slices of beef. Skip this step, and there’s a good chance you’ll be chewing shoe leather.

Vinegar and lime juice are both great with flank steak. I also tested this recipe with buttermilk, but I personally didn’t care for it and thought the vinegar and lime juice did a better job of both seasoning and tenderizing the beef.

For this recipe, I used a combination of white wine vinegar and lime juice.

HOW LONG SHOULD I MARINADE FLANK STEAK?

I came across some research that said you shouldn’t marinade flank steak longer than two hours because it could “scorch” or toughen the meat. The reason you’ll see this is because acid breaks down proteins, and when those proteins break down too much water is released and the muscle becomes tough.

But marinades in tighter cuts of meat like flank steak really don’t penetrate deep into the tissue like they would with fish, so you have a little more leeway.

I tested this marinade after two hours, and again after eight hours. Both times the meat was tender and flavorful. I also tried it after 24 hours and found the meat a little tough compared to the others. Just to be on the safe side, I wouldn’t marinade this overnight.

CAN YOU MARINADE AND FREEZE FLANK STEAK?

Feel free to freeze this steak with the marinade! Make the marinade in a zip top bag, add the steak and turn to coat. Squeeze as much air out as possible, then store it in the freezer for up to 3 months.

Take the steak out of the freezer and thaw it in a bowl of water a couple of hours before you want to grill it or the morning before you plan to grill it.

HOW TO GRILL FLANK STEAK

Flank steak is an odd shaped cut where one end is usually thicker than the other by as much as an inch. This alone can make cooking it a challenge, but this is actually an easy problem to solve using one of two methods.

• Method 1: Pound it thin. Cover the surface of the steak with parchment or plastic wrap. Then use either a meat mallet or heavy skillet to pound the thickest part of the steak until it’s closer in size to the thinner parts. Then marinade as directed.
• Method 2: Cook it over two heat zones. Create a hot and warm zone in your gas or charcoal grill. Place the thickest part of the steak on the hot zone, and the thinner part over the warm zone. This is my preferred method.

HOW LONG TO GRILL FLANK STEAK

Lean cuts of meat like flank steak are really best when served medium rare. If you cook it to the medium stage or beyond, the meat is tough and chewy rather than juicy and succulent, so shoot for medium rare even if it’s not your normal range.

Remember, too, that time is variable. To get a perfectly cooked steak every time, insert a meat thermometer through the side of the thickest part of the steak.

• Medium: 8 minutes per side (145°F)
• Medium Rare: 6 to 7 minutes per side (135°F)
• Rare: 5 to 6 minutes per side (125°F)

These times are based on cooking the steak with the two-zone method, not the method of pounding the meat thinner. The cooking times may be faster if you used the pounding method.

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