Medium-Rare Sous Vide Flank Steak: Perfect Results Every Time (2025)

Growing up, I thought flank steak was one of the trickiest cuts to master. It was the cut my dad always grilled at family cookouts in sunny Florida, often sliced thin for fajitas or served with chimichurri. Sometimes it turned out juicy and flavorful, but just as often it came off the grill a little too dry or a bit too chewy. The lean nature of flank steak always left a narrow margin between tender and tough.

Everything changed the first time I tried medium-rare sous vide flank steak. When I got my first sous vide machine, I was eager to test it on cuts that had always been challenging—and flank steak was right at the top of my list. I remember prepping the steak, scoring it with a sharp knife, seasoning it well with kosher salt and oregano, and sealing it up for the bath.

As it gently cooked at 129°F for a couple of hours, I kept thinking, could this really work? When the timer went off and I pulled the steak from the bag, it looked promising. But the real test came after that final sear. I sliced into it—and there it was: a beautifully even medium-rare sous vide flank steak, perfectly pink from edge to edge with none of the dryness I used to battle on the grill. I was instantly hooked.

Why does medium-rare sous vide flank steak work so well? First, it’s the precision cooking. Flank steak is lean and flavorful, but those long muscle fibers can easily turn tough if exposed to high heat for too long. That’s why traditional grilling sometimes dries it out. But sous vide changes the game. The consistent water bath holds the flank steak at the exact medium-rare temp—right around 129°F to 131°F—so there’s zero risk of overcooking. It slowly breaks down just enough connective tissue to keep the meat juicy while preserving a satisfying bite. Every time I make medium-rare sous vide flank steak, I know it’ll come out exactly as I like it, without the guesswork or constant monitoring.

Another thing I love? How versatile medium-rare sous vide flank steak is. Whether I’m craving steak tacos, a hearty steak salad, or just a beautifully sliced steak with roasted veggies, this method delivers. One of my go-to quick dinners is building flavorful bowls with medium-rare sous vide flank steak, quinoa, and fresh veggies. It’s also fantastic for meal prep because the steak holds its texture and flavor beautifully, even when reheated. And when I want to keep things classic, a hot cast iron skillet is the perfect way to finish off medium-rare sous vide flank steak with a crave-worthy sear.

I often tell friends who are new to sous vide cooking: start with medium-rare sous vide flank steak. It’s forgiving, flavorful, and gives that “wow” moment when you slice into it. Plus, it’s a great base for all kinds of variations. When I want to change things up, I love making sous vide flank steak tacos with pickled onions and a bright salsa verde. Or I’ll experiment with other cuts like this zero-stress sous vide steak when I feel like trying something new. But no matter how many other recipes I test, medium-rare sous vide flank steak remains one of my all-time favorites. There’s just nothing like that perfect pink slice with a bold, seared crust—every single time.

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What Temperature is Medium Rare Flank Steak Sous Vide?

When it comes to medium-rare sous vide flank steak, I’ve found the sweet spot for temperature is between 129°F and 131°F. Personally, I aim for 129°F every time—it delivers the perfect balance of tenderness and juiciness, with a beautifully pink center from edge to edge. At this precise temperature, medium-rare sous vide flank steak retains just enough structure and bite to satisfy, while remaining wonderfully moist and flavorful. If you prefer your steak a touch more cooked, bumping it up slightly to 131°F still results in a delicious steak—slightly firmer but still in the medium-rare range.

What makes medium-rare sous vide flank steak so reliable is the control this method gives you. Traditional cooking methods—grilling, broiling, pan-frying—can easily overshoot that ideal doneness. With sous vide, though, you hold the steak exactly at the target temperature for as long as you like, ensuring every inch is perfectly cooked. No more slicing into the steak to check for doneness. No worries about carryover cooking or guessing when to pull it off the heat. Instead, you get medium-rare sous vide flank steak done perfectly—every single time.

Another bonus is consistency from one cook to the next. Whether you’re making medium-rare sous vide flank steak for a casual weeknight dinner or serving it to friends at a weekend gathering, you’ll always know what to expect. The even cooking is especially important with flank steak, which can easily turn tough if overheated. By keeping it at 129°F to 131°F, sous vide preserves the natural flavor of the meat while gently transforming the texture into something truly special. It’s one of the reasons I keep coming back to this method anytime I’m craving medium-rare sous vide flank steak at home.

How Long to Sous Vide Flank Steak for Medium Rare

Timing is another key factor when cooking medium-rare sous vide flank steak. Because flank steak isn’t a very thick cut—usually around one to one-and-a-half inches—you don’t need the long cook times required for something like brisket or short ribs. For medium-rare sous vide flank steak, I typically aim for a cook time of 2 to 4 hours. In my experience, two hours is plenty to deliver juicy, tender results. But one of the great advantages of sous vide is flexibility. If your schedule allows, leaving medium-rare sous vide flank steak in the bath for up to four hours will help soften the muscle fibers even more, without breaking down the texture too far.

One of the things I love most about cooking medium-rare sous vide flank steak is how forgiving it is. Once your steak is sealed and in the water bath at your target temperature—say, 129°F—you can let it go an extra hour or two without worrying about overcooking. That’s the beauty of sous vide: the steak can’t rise above the set temperature, so your results stay consistent. If I’m entertaining or juggling other dishes, I don’t stress about precise timing because I know my medium-rare sous vide flank steak will still come out just right.

For thicker cuts, or if I’m cooking for a bigger crowd, I might adjust the time slightly—just like I do when preparing this sous vide steak recipe, which is a great reference if you want to branch out beyond flank. But for lean, flavorful medium-rare sous vide flank steak, sticking with 2 to 4 hours at 129°F to 131°F always produces a reliably tender, melt-in-your-mouth result. Once you experience that perfect texture, it’s hard to go back to any other method.

Here’s a quick guide:

Doneness	Temperature (°F)	Time Range
Rare	123–127°F	2–4 hours
Medium Rare	128–134°F	2–4 hours
Medium	135–140°F	2–4 hours
Well Done	141–150°F	2–4 hours

For other cuts like picanha, check out my sous vide picanha steaks—they also benefit from this precision cooking!

How to Score, Season, and Seal Flank Steak for Sous Vide

One of the easiest ways to ensure tender, flavorful medium-rare sous vide flank steak is by taking a few minutes to score it before cooking. Using a sharp knife, lightly score the surface of the steak in a crosshatch pattern on both sides. This simple step allows seasoning to better penetrate the meat and also makes it easier to slice once cooked. Whenever I prepare medium-rare sous vide flank steak, this quick scoring step helps deliver that signature bite and bold flavor.

Next comes seasoning. For medium-rare sous vide flank steak, I love keeping it simple—a generous sprinkle of kosher salt and finely chopped fresh oregano is my go-to blend. Kosher salt helps enhance the natural flavor of flank steak, while the oregano adds a subtle herbal note. Be generous when seasoning both sides of your steak, though you likely won’t need all of the salt mixture. I usually store any extra in a small jar for my next medium-rare sous vide flank steak night.

Once seasoned, the steak is ready to seal. For medium-rare sous vide flank steak, you can vacuum seal it or use a freezer-safe zip-top bag with the water displacement method. I use both techniques interchangeably depending on what’s clean and handy. The goal is to remove as much air as possible, which helps ensure even cooking and great results. Once sealed, your medium-rare sous vide flank steak is ready for its water bath.

If you’re curious about trying this method with other cuts, I highly recommend this flat iron steak sous vide recipe. The techniques—scoring, seasoning, sealing—translate perfectly and give you the same level of control and delicious results as you’ll get with medium-rare sous vide flank steak.

How to Sear Sous Vide Flank Steak for the Best Crust

The sear is where the magic happens when cooking medium-rare sous vide flank steak. After your steak comes out of the water bath, take the time to pat it very dry with paper towels. This step is critical—a dry surface is the secret to getting that gorgeous, golden-brown crust without steaming the meat. For medium-rare sous vide flank steak, a perfect crust really elevates the flavor and adds irresistible texture.

I almost always sear medium-rare sous vide flank steak in a hot cast iron skillet. Cast iron holds heat incredibly well, giving you that deep, even sear. My fat of choice is ghee—it handles high heat beautifully and adds a subtle, nutty richness that complements the steak. Once your skillet is smoking hot, add a spoonful of ghee.

Then, carefully lay the steak in the pan and sear each side for about 30 seconds to 1 minute. You’re aiming for a dark, caramelized crust while keeping the inside a perfect medium rare. The beauty of medium-rare sous vide flank steak is that it’s already cooked exactly to temperature, so the goal of searing is purely to add flavor and texture—not to cook it further.

One more important tip: after searing, always slice medium-rare sous vide flank steak against the grain. Flank steak has long muscle fibers, and cutting across them ensures each bite is tender and easy to chew.

If you’re looking to add even more flavor, you can also finish medium-rare sous vide flank steak with a compound butter or flavored fat. I’m a big fan of the cowboy butter technique in this sous vide steak with cowboy butter recipe—garlic, herbs, and butter pair beautifully with the bold beefy flavor of flank steak.

How to Slice and Serve Medium-Rare Sous Vide Flank Steak

The final step is slicing—don’t skip this! Flank steak has long muscle fibers, so slicing against the grain is crucial. After letting the steak rest for a few minutes, cut it into ½-inch slices across the grain. This shortens the fibers and gives you beautifully tender bites. I like to sprinkle a little of the reserved salt blend right before serving for an extra pop of flavor. Medium-rare sous vide flank steak is super versatile—serve it as the main dish, over salads, in bowls, or tucked into sandwiches. For a quick dinner, I often pair it with grilled veggies or roasted potatoes.

Favorite Side Dishes and Marinade Ideas

Though this steak is fantastic with just salt and herbs, you can easily switch up flavors. A simple garlic marinade, a splash of soy and lime, or even chimichurri pairs beautifully with flank. One of my favorites? Using this steak in sous vide flank steak tacos—it’s a weeknight win.

For sides, think bold and fresh: grilled asparagus, chimichurri, roasted sweet potatoes, or a crisp green salad. If you want more beefy ideas, I also recommend trying this sous vide beef chuck roast when you’re in the mood for heartier fare.

Conclusion

There you have it—everything you need to know to make medium-rare sous vide flank steak that’s juicy, tender, and full of flavor. From the perfect temperature (I swear by 129°F) to smart prep, to that crave-worthy sear, this method takes the guesswork out of flank steak. Whether it’s a weeknight dinner or part of a feast with friends, you’ll love how easy it is to get reliable results. I hope this guide helps you enjoy sous vide cooking as much as I do. Ready to give it a try? Let’s get that water bath going!

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FAQs

What temperature is medium rare flank steak sous vide?
Medium rare is typically 128–134°F. I prefer 129°F for a perfect pink center.

How long do you cook flank steak for medium rare?
Sous vide flank steak for 2 to 4 hours for juicy, tender results.

How long to cook a medium rare steak in a sous vide?
It depends on thickness—flank steak does great at 2 to 4 hours.

How long to sous vide flank steak reddit?
Most home cooks on Reddit suggest 2 to 4 hours for flank steak at medium rare.

What temperature is good for flank steak?
For medium rare, 129–131°F. Medium is 135°F.

How long to sous vide steak medium rare reddit?
Typically 1½ to 4 hours, depending on cut and thickness.

Is flank steak better, medium or medium rare?
I find flank steak best at medium rare—juicy and still tender.