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How Long to Marinate Flank Steak

By: Author William Thomas

William Thomas

Editor-in-Chief & Pitmaster

I have been smoking and grilling meat from an early age and enjoy sharing my knowledge and expertise through the hundreds of articles I have written about BBQ. I hope to make everyone’s BBQ journey that little bit easier.
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How Long to Marinate Flank Steak

Flank steak is a versatile, delicious cut of beef that is lean, so it’s the perfect way to get your fill of beef without racking up too many calories.

However, flank steaks are fairly tough, so they are the perfect cut for marinating. The key is knowing how long to marinate flank steak. 

What is Flank Steak? 

Flank steak is a hefty cut of beef fabricated from the bottom portion of the cow’s abdominal area. 

The flank is a muscle used quite often, meaning it has minuscule amounts of fat. Unfortunately, this also means the flank steak is very tough. 

Flank steak is sold as a whole cut instead of being fabricated into smaller portions. Therefore, it is a long, flat cut of beef that is fairly uniform in thickness.

The average flank steak weighs 1 1/2-3 pounds. 

You can expect rich, potent, and robust beef flavor from eating flank steak. However, the steak can be a little tough since it doesn’t have fat that renders out as it cooks. 

Does Flank Steak Need To Be Marinated?

Some folks allege that you do not have to marinate flank steaks. However, I say otherwise. 

Remember, flank steaks are tough. Therefore, if you do not marinate the flank steaks, they will become chewy, and no one likes a chewy steak. 

I get it; sometimes, you do not have time to marinate flank steaks. However, marinating flank steak is the best way to tenderize it. 

Marinating flank steaks in acids like lemon juice, lime juice, or vinegar can break down the steak’s tough muscles creating a tender flank steak. 

Plus, the most significant benefit of marinating flank steak is that you will be adding lots and lots of delicious flavor. 

Can Flank Steak Be Marinated Too Long?

Just like chicken and salmon can be marinated too long, flank steak can be marinated for too long. In short, leaving the flank steak in the marinade for too long will ruin the steak.

Instead of a tender, juicy steak, you will end up with a tough, chewy steak. 

How Long To Marinated Flank Steak? 

Technically, you can leave the marinated flank steak in the fridge for up to 5 days. However, this only speaks to food safety issues. After 5 days, the flank steak will start to spoil. 

Most flank steak marinade recipes are designed to work much quicker than 5 days. At a minimum, you should marinate the flank steak for 2 hours.

However, do not exceed 12 hours. After 12 hours, the flank steak will start to toughen up. 

Tips For Marinating Flank Steak 

Marinating flank steak involves more than whisking a few ingredients in a bowl and adding the steak. These are a few tips you should use when marinating flank steak. 

First, marinate the flank steak in food-safe containers. Ziplock bags are best for marinating flank steak.

They allow the marinade to surround the steak. If you were to marinate the flank steak in a bowl, the marinade would sit at the bottom of the bowl, so the pieces at the bottom of the container would absorb most of the marinade’s flavor. 

Make sure you use to press the air out of the flank steak before sealing the bag. Roll the bag into a log so the marinade covers every inch of the flank steak.

In addition to this, if you use a ziplock bag, you can toss it in the trash once you have removed the flank steak from the bag. 

Nevertheless, if you do not have ziplock bags, you can marinate your flank steaks in food-safe glass, plastic, or stainless-steel containers. 

You can score the flank steak so the marinade can penetrate the inner layers of the meat. However, this is optional.

To score your flank steak, cut 4-5 diagonal cuts that are 1/4-inch deep across the grain of the steak using a sharp knife. Proceed with the marinade as directed. 

If the flank steak is marinated in a bowl or shallow baking dish, turn them every so often. This will make sure the marinade is evenly distributed. 

Marinate your flank steak in the fridge. Flank steak cannot sit at room temperature for more than 2 hours. It takes 2-12 hours for flank steaks to marinate; leaving them at room temperature is out of the question. 

After 2 hours, the flank steak will become riddled with so many bacteria that it is unsafe to consume.

Ultimately, if you consume flank steak that sat out for more than 2 hours, you or anyone who eats the steak can end up with food poisoning. 

Remove the flank steaks 30 minutes to an hour before you intend to cook them. This gives the flank steak a chance to come down to room temperature, so it cooks evenly. 

Do not reuse flank steak marinades. If you wish to reuse the marinade, place it into a pot and set it over medium-high heat. 

Once the marinade comes to a boil, let it cook for 1 minute until it has a temperature of 165°F. The heat will neutralize any bacteria that would cause food poisoning. 

Nevertheless, if you want to baste the steak with marinade or serve some of the marinades with the flank steak, remove a portion of the marinade before you add the steak. 

How to Marinade Flank Steak

All of this talk about flank steak is bound to make you hungry. So, here’s how to marinate flank steak. Combine olive oil, garlic, salt, lemon or lime juice, soy sauce, and brown sugar in a bowl.

Place the marinade into a ziplock bag, then add the flank steak. Press the air out of the flank steak, seal the bag, and massage the marinade into the meat. 

Place the flank steak onto a baking sheet so it lays flat. Place the flank steak into the fridge and let it marinate for 2-12 hours. 

Final Thoughts

Marinating flank steak is one of the best ways to soften up the steak. However, if you marinate it for more than 12 hours, you are bound to end up with tough flank steak.

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