Sous vide flap steak is an absolute game changer. This revolutionary method allows you to make perfectly juicy, tender steak, every single time. Time to say goodbye to the days of overcooked steak, and hello to that brilliant edge to edge medium-rare.
In this recipe, we will walk you through everything you need to know to make the best flap steak of your life. From what temperature to sous vide, how long to cook the flap steak, to different searing methods, this recipe has it all.
An essential part of cooking sous vide is putting ingredients in an air-tight bag or container. The two most common techniques to package your ingredients are vacuum sealing and using the water displacement method.
A vacuum sealer removes all the air and seals the contents of a plastic bag through a vacuum. Ensuring the food is airtight and properly sealed prevents the bag from floating, which can result in uneven cooking. If you are in the market for a vacuum sealer, I’d recommend the Anova sealer.
The displacement method is a technique where you first place your food and marinades in a sous vide bag, submerge the bag in a container of water, and allow the pressure to force all the air out of the bag.
Either method works for this recipe. Note that if you are adding a marinade in the bag, please make sure your vacuum sealer is capable of sealing liquids. If not, please use the displacement method.
Flap Steak Time and Temperature
Through loads of experimentation, we’ve found that cooking flap steak at 54C/129F for 2 hours is the perfect combo. Cooking the flap steak for two hours break down the connective tissue (collagen), which results in extremely tender, juicy beef. Also, cooking the steak at a temperature of 129F ensures that the beef is a beautiful medium rare with great texture.
Although this is our favorite time and temperature, we recommend you explore different combinations to find your personal favorite. Our cooking guide can always help you find your perfect time and temperature.
Can You Sous Vide Frozen Steak?
The quick answer is, absolutely! Cooking frozen foods sous vide is an ultra convenient, safe way to prepare your protein. Just take the food directly from the fridge, repackage it (unless you know the bag is sous vide safe) and let the sous vide work its magic.
The only thing you’ll need to adjust is the cook time. If you are cooking frozen flap steak sous vide we recommend adding an additional hour to the cook time, so three hours total.
Best Way to Sear Beef After Sous Vide
Searing is the most critical step in the sous vide process. Getting a deep, rich sear can make your food look like it is Michelin star quality. Failing to do so will make your dinner guests wonder why they let you cook again.
If you want to get an amazing sear on your steak, you’ve got to:
1. Pat the meat completely dry with a paper towel
2. Season generously with salt or seasoning of your choice
3. Sear at extremely high temperatures.
First, pat the meat completely dry using paper towels. After the meat is dry, lightly brush the steak with olive oil then season generously with salt and pepper or a seasoning of choice. Note that brushing with olive oil is optional, but will allow the seasoning to stick to the meat better and results in a deeper sear.
At this point you want to determine the best searing method. For flap steak, we suggest pan searing, grilling or using a searing torch. The trick is getting the pan, grill or torch extremely hot, then searing for 1 to 2 minutes on each side. This results in a quick, high-quality sear without overcooking the steak.
Sous Vide Machine – This one is obvious. To cook sous vide, you’re going to need a device to precisely regulate the temperature of the bath water. The two best sous vide machines in the game right now are the Anova Precision Cooker and the Breville Joule.
The main difference between the two is that with the Anova you can control the device both manually and with a mobile device, and with the Joule you can only control the device by using your mobile device. Either way, both sous vide machines are top class and you can’t go wrong with either choice.
12-quart Container – Although you can use a basic stockpot for your sous vide cooking needs, I highly recommend buying a large plastic container. They are inexpensive and spacious, so you won’t have to worry about cooking a big roast in a small pot. I recommend a 12 quart Rubbermaid container, as it is BPA free, sturdy, and large enough for just about anything you will be cooking.
Container Lid – If you are going to buy a plastic container, I highly suggest buying a compatible lid for it. When you sous vide for a long duration, the heat of the water causes evaporation. With a lid, it eliminates a majority of the evaporation so you can cook for hours care-free.
Cast Iron Skillet – If you are looking to take your searing game to the next level, we recommend investing in a cast iron skillet. By using a cast iron in this recipe, you’ll achieve a deep sear on the protein. Cast irons are also extremely handy for searing just about any and all sous vide meat. Lodge offers the best quality and price, which is why it is our favorite cast iron brand.
Check out our full list of recommended gear here.
Sous Vide Flap Steak Recipe
- 1 - 2 lbs flap steak
- Salt and pepper (or seasoning) to taste
Set sous vide machine to 54C/129F.
Season flap steak lightly with salt or a seasoning of your choice. Place meat in sous vide bag and remove the air through a vacuum sealer or the displacement method. Drop the bag in the bath for two hours.
Remove bag from bath. Take steak out of the bag, pat dry with paper towels and season with salt and pepper (or seasoning) to taste.
Heat up large skillet on high and add oil. Sear flap steak for 1 to 2 minutes on each side. Remove from pan, and place on a plate to rest for 5 minutes. Once rested, serve and enjoy! Alternatively sear the beef on a grill or using a searing torch.