Flat iron steak is one of the newer cuts to become mainstream. Cut from the shoulder area, it used to be considered a waste cut because it was too full of connective tissue to eat. However, experts have learned how to cut in a way that removes this connective tissue to reveal edible meat that’s flavorful and, when cooked correctly, tender.
Sous vide helps get flat iron steak to an ideal tenderness by cooking it at a consistent temperature in water. Learn how to sous vide flat iron to get these delicious results to your table.
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Preparation for Sous Vide Flat Iron
To sous vide flat iron steak, you’ll need sous vide bags, a precision cooker or pot with a water bath, your choice of spices and herbs, and a skillet with olive oil. Preheat the precision cooker or water bath to 130 degrees. Season the steak on both sides with salt, pepper, and your choice of spices. Then, add the steaks to the sous vide bag along with fresh herbs, like rosemary or thyme, if preferred.
Sous vide flat iron takes 1-2 hours to cook. Generally, your steak will be done at about the one-hour mark, but you can let it cook for up to two hours. After that, searing takes about five minutes, allowing you to sous vide flat iron in about 1 ½ – 2 ½ hours.
Your final steak temperature should reach between 130°F-135°F for medium-rare. Use the following chart as a guide for each level of doneness.
Cooking to Medium Rare
To cook medium-rare flat iron using sous vide, start by setting the temperature of the water bath to 130 degrees. Season steaks and add them to the sous vide bags, finishing by removing air from the bags as you seal them. Submerge the bags in the water bath and cook for 1-2 hours. Sear steaks on a preheated skillet for 1-2 minutes on each side. Then, rest for 5 minutes on a foil-tented plate. Use a thermometer to ensure that the steak reaches a final temperature of 130°F-135°F.
Flat Iron Sous Vide Tips
We want to share a few tips that will help you learn how to sous vide flat iron like a true chef:
Slice It the Right Way
Many people prefer to slice flat iron after cooking it. If you choose to do so, be sure to cut it correctly. The right way to slice flat iron is against the grain, meaning that your knife should cut in the opposite direction as the lines that run through the steak. Start slicing only after you’ve allowed the steak to rest for 5-10 minutes to allow the meat to reabsorb its juices.
Don’t Cook It Too Long
Avoid cooking flat iron using the sous vide method for longer than two hours, regardless of the type of cook you prefer. Doing so can make the meat lean toward the mushy side rather than have the pleasant chew you usually get from steak. If you prefer a level of doneness higher than medium-rare, use the chart above to determine the right cooking temperature rather than cooking it for longer in the water bath.
Check Its Temperature
Always rely on a thermometer to check the temperature of your flat iron steak before eating it. This is a much more accurate method than using your fingers or eyes to gauge the doneness of your steak. Remember, the temperature will rise a few degrees during the searing and resting process, so it’s okay if your steak is just a few degrees below its final temperature range after removing it from the water bath.
Choosing the Right Cut
How do you choose quality flat iron steak? First, look for Premium Angus, USDA Prime, or Wagyu selections. These labels indicate the highest quality steaks you can buy based on marbling and overall quality. Also, find flat iron steaks labeled as wet-aged or dry-aged, a process that allows steaks to age over time in a controlled environment to enhance their texture and flavor. We have aged, high-quality flat iron steaks available for ordering online at Chicago Steak Company.
Sous Vide Flat Iron Instructions
The following step-by-step instructions pair with the recipe below to help you learn how to sous vide flat iron steak like a professional.
Step 1: Prepare to Cook
Gather everything you’ll need to sous vide flat iron steak, including a precision cooker, sous vide bags, salt, pepper, and a cast-iron skillet. Set the precision cooker’s water bath to 130 degrees for medium-rare.
Prepare the steaks by adding salt and pepper generously to both sides. If you used a marinade, you can skip this step and go straight to bagging the steak.
Add the steak to sous vide bags. You may need to portion large flat iron steaks to fit into the bags. Add a teaspoon of the marinade to each bag if used. Seal the bags, removing as much air as you can.
Step 2: Sous Vide Method
Use tongs to lower each bag into the water. Do this slowly to avoid splashing. The bags should be completely submerged. Cook for one hour or up to two hours maximum. Be sure to use a timer for accuracy.
Step 3: Finish Up
Remove the bags from the water with tongs. Open them over the sink to release drainage. Preheat a cast-iron skillet with a drizzle of olive oil to medium-high heat. Sear for 1-2 minutes on each side until golden brown.
Move steaks to a foil-tented plate to rest for 5 minutes before slicing or serving. Enjoy!
Sous Vide Flat Iron Recipe
Prep time: 10 minutes
Cooking time: 1 ½ hours
- 1 ½ – 2 pounds of flank steak
- Marinade (optional)
- Olive oil
- Preheat water bath to 130 degrees for medium-rare. Season both sides of the steak with salt and pepper. If using a marinade, you can skip this step. Place steak into sous vide bags and remove as much air as possible.
- Submerge the bags into the water carefully. Set a timer for one hour, or up to two hours, maximum.
- Carefully remove the steaks from the bags and pat them dry. Preheat a skillet over medium-high heat. Sear for 1-2 minutes on each side. Rest for five minutes before slicing or serving.
Sous Vide FAQ’s
Is flat iron good for sous vide?
Yes, flat iron cooks well with sous vide. This cooking method cooks flat iron — a relatively thin cut — slowly to prevent it from drying out like it can in a skillet, in the oven, or on the grill.
What temperature do you cook flat iron sous vide?
For medium-rare, cook flat iron sous vide at 130 degrees. For medium, cook at 140 degrees, medium-well 150 degrees, and 160 degrees for well-done.
Should I sear flat iron after cooking sous vide?
You don’t need to sear flat iron after cooking it using the sous vide method, but we recommend doing so to enhance its flavor and texture. Searing leaves a slight crisp on the outside and helps hold in the meat’s juices.
Should I use a marinade for sous vide flat iron?
A marinade is entirely optional for sous vide flat iron. However, some home cooks prefer using one to add some flavor to the meat. If you’d like to use a marinade, allow the flat iron to remain in the liquid for at least two hours in the refrigerator before cooking.
Sous Vide Flat Iron Steak
- 1.5-2 lbs flat iron steak
- marinade (optional)
- olive oil
- Preheat water bath to 130 degrees for medium-rare. Season both sides of the steak with salt and pepper. If using a marinade, you can skip this step. Place steak into sous vide bags and remove as much air as possible
- Submerge the bags into the water carefully. Set a timer for one hour, or up to two hours, maximum
- Carefully remove the steaks from the bags and pat them dry. Preheat a skillet over medium-high heat. Sear for 1-2 minutes on each side. Rest for five minutes before slicing or serving