How To Sous Vide Flat Iron Steak Without Immersion Circulator

Last Updated on by SteakEat

[nextpage title=”Part 1″ ]

This article explains how to sous vide flat iron steak, using a simple recipe and minimum tools to illustrate the method behind.





[wpanchor id=”1″]

Part 1: Ingredients & Sous Vide Tools

The ingredients we’ll be using:

  • 1-inch thick flat iron steak
  • 1 tsp ghee or coconut oil
  • 1 tbsp organic grass-fed butter
  • Kosher/flaked salt
  • Freshly ground black pepper

With the following tools:

  • Dutch oven
  • Food-safe plastic bag*
  • Oven safe candy/oil thermometer
  • Meat tongs
  • Paper towels
  • Blowtorch or Skillet

Got them all? Let’s SteakEat!

steakeat-approvedFREE Bonus:

Tired of ads and scrolling?

Avoid them – [ninja-popup ID=2903]download this ‘How to Sous Vide Flat Iron Steak’ Guide in PDF format.[/ninja-popup]

It is convenient, EASY-to-print and includes these awesome photos from below!

[wpanchor id=”2″]


Part 2: Sous Vide Flat Iron Steak in 5 Steps

The idea behind sous vide is simple.

Seal your steak inside a food-safe vacuum plastic bag and leave it in water, warmed up to a certain temperature for a couple of hours.

Then sear the steak with blow torch or in skillet in order to develop surface browning.

Now let’s look into details. 🙂

[dropshadowbox align=”center” effect=”vertical-curve-both” width=”autopx” height=”” background_color=”#ffffff” border_width=”1″ border_color=”#dddddd” ]

Step 1: Fill up Dutch Oven

Start with a Dutch oven and fill it about 2/3 full of warm water. Ideally fix a candy or oil thermometer so that it measures the temperature of the water.

Start heating it up on the stove or inside the oven (I recommend the oven, since it gives a more even type of heat).


[dropshadowbox align=”center” effect=”vertical-curve-both” width=”autopx” height=”” background_color=”#ffffff” border_width=”1″ border_color=”#dddddd” ]

Step 2: Sous Vide Flat Iron Steak Temperature

Increase the temperature of the water to the correct temperature over a medium heat.

So if you’d like a medium-rare flat iron steak, go for 55C / 130F water temperature.

If you are going for rare or medium level of doneness, use 50C / 122F and 60C / 140F temperature setting respectively.



[nextpage title=”Part 2″ ]

[dropshadowbox align=”center” effect=”vertical-curve-both” width=”autopx” height=”” background_color=”#ffffff” border_width=”1″ border_color=”#dddddd” ]

Step 3: Zip the Steak

Place your flat iron steak into a zip lock plastic food-safe bag and squeeze out all of the air before sealing the zip lock*.

Note that we don’t add any salt or pepper now.

Salt will deteriorate flat iron’s surface, while pepper will burn, when we sear the steak later.

There were some health concerns, regarding plastic leaching endocrine disrupting chemicals into food (not just during cooking). As for now sous vide community found the least harmful alternative to “food-safe” plastic zip lock bags – silicone bags, which can be used more than once. 


[dropshadowbox align=”center” effect=”vertical-curve-both” width=”autopx” height=”” background_color=”#ffffff” border_width=”1″ border_color=”#dddddd” ]

Step 4: Sous Vide Cooking Times

Immerse the steak bag in the Dutch oven with the temperature set according to the level of doneness you want to achieve (55C / 130F for medium-rare) and cook it for the time required depending on thickness:

Thickness                           Required cooking time

0.25 inches                        23 minutes
0.5 inches                           31 minutes
1 inch                                   60 minutes
1.5 inches                           1 hour 45 minutes
2 inches                               2 hours 50 minutes
2.5 inches                           4 hours 15 minutes
3 inches                               6 hours

Remember – you can’t overcook the steak, if the temperature is fixed, so, even if you forget about your cooking and come back in 3 or 4 hours, your steak will not be overcooked. In fact, there is a good chance it will even be more tender and flavorful!

However, keeping constant temperature inside the oven and leaving it unattended is a risky business…

This is why, if you find yourself falling in love with sous vide, I recommend you either get a sous vide minioven or an immersion calculator like this.


[dropshadowbox align=”center” effect=”vertical-curve-both” width=”autopx” height=”” background_color=”#ffffff” border_width=”1″ border_color=”#dddddd” ]

Step 5: Brown the Surface

Once you are done sous viding, you now need to sear the flat iron’s surface.

I love using blow torch, because it so easy and requires zero preparation, but I of course show how to use classical stove top method.

Let’s start with the blow torch instructions and then look at how we can use skillet instead.


Searing Flat Iron Steak with Blow Torch

The aim is to sear the outside without affecting the meat immediately inside.

Remember, the whole point of sous vide is to have a consistently cooked piece of steak so the thin crust that a flat iron steak will take on after searing with a blow torch is perfect.

To sear your flat iron steak after sous vide:

  1. Remove it from the zip lock bag after the required amount of time has passed.
  2. Pat it completely dry with paper towels.
  3. Season with coarse Kosher salt.
  4. Light your blow torch and turn it to the highest heat.
  5. Apply the flame evenly to the surface and edges of the flat iron steaks until a golden browned crust develops.
  6. Season your steak with freshly ground pepper.
  7. Then cut and serve.

HINT: Make sure it’s a professional blow torch, which can generate enough heat to sear the steak immediately. Less powerful torches, often used for creme brulees, will not have the same effect.


Searing Flat Iron Steak in Skillet After Sous Vide

The goal is to sear the steak surface as quickly as possible. It means you should heat up the skillet really well.

  1. Remove the steak from the bag, pat it dry with paper towels and season with kosher salt.
  2. Add a tablespoon of ghee or coconut oil to the skillet and heat it up. You will know it’s ready, when you see gentle smoke coming off it; then wait for another 10 seconds to make sure the pan is hot enough.
  3. Put the steak inside the skillet and sear it for 1 minute per side so it develops the surface browning.
  4. Once ready, rest the steak for two minutes on a plate, season with freshly ground black pepper, cut and serve.

BONUS TIP: Once you are 30 seconds away from finishing to sear the second side, add the tablespoon of organic grass-fed butter. It will explode the flavor and help browning the sides!


steakeat-approvedFREE Bonus:

[ninja-popup ID=2903]Download this ‘How to Sous Vide Flat Iron Steak’ Guide in PDF format.[/ninja-popup]

It is convenient, EASY-to-print and includes these awesome photos from above!


[nextpage title=”Part 3″ ]

Part 3: Buying Guide & Utensils

Now I will explain you more about how I choose a quality flat iron steak and cooking utensils.

Let’s start with the steak. Here is one rule which gives me the best results:

Organic grass-fed. You are what you eat and that applies to beef. If cows eat tasteless grain, antibiotics and growth hormones, then you shouldn’t expect much flavor and health benefit. That’s why I choose organic grass-fed flat iron steak whenever possible. Not only I get the most flavor, I get a ton of vitamins, minerals and satisfaction.

What about quantity? How much steak is necessary?

A good rule of thumb is 200g / 7oz per person. This quality is just right for satiation without getting stuffed. If that’s too much/little, you can adjust it next time.

That’s it with steak from my perspective. Notice how I didn’t mention any fat streaks for when you are choosing beef… The reason is that I don’t believe fat has anything to do with the quality of beef.

All you need is organic grass-fed beef. Now – cooking utensils.


Utensils You Need To Sous Vide Flat Iron Steak

Dutch Oven

Truth be said, you can use any saucepan, but Dutch oven is preferable because of its thick walls and its ability to hold heat fairly well. It’s especially important when you don’t use an immersion circulator, which automatically adjusts water temperature. That way Dutch oven can still hold the water temperature for a while, even if the external heat intensity reduced. I recommend using appropriate size Dutch oven if you don’t own an immersion circulator or a special sous vide minioven.


Candy/Oil Thermometer

You will need this simple piece of equipment to monitor the water temperature. You can also use your oven-safe meat thermometer if you have one.



We use salt to develop the flavor on the steak’s surface when searing it with blow torch or on stove top.

I recommend using coarse kosher salt – its density is lower than that of table salt, so you can put more of it without overshooting the mark.



Freshly ground pepper is perfect for when your steak is already seared. I don’t recommend buying ground pepper – it’s susceptible to the atmosphere and loses both, flavor and aroma, when not used quickly enough.

Grind your black peppercorns right before serving the steak.


Food-Safe Plastic Bags

Your simple solution for a once-off sous vide session is a food-safe resealable zipper storage bag.

However there are concerns regarding chemicals from these leaching into meat even when being cooked at low temperature like 55C / 130F.

If you are really into sous vide, try minimizing possible negative impacts by using special sous vide cooking pouches.


Paper Towels        

Pat drying is a must before searing the steak’s surface and that’s why we need paper towels. Get a roll and keep it in your kitchen for things like this.


Blow Torch

I use blow torch for searing flat iron steak’s surface after sous vide cooking – it’s fun!

One thing you need to be aware of is blow torch power. Crème Brulee style torches are of no use and will boil your steak instead of searing it.

If you are planning to invest in a tool of that caliber, I recommend going for something like this instead. It costs twice as much as ‘crème brulee’, but it does the job and won’t break in a long time. After all most of us are not that rich to afford buying cheap things.


If you don’t have a blow torch, you will need this instead:



Thick-walled heavy skillet is ideal. Forged aluminum is my choice for its non-sticky properties and even heating. You only need the skillet to quickly sear the steak’s surface, so there is no need to go very fancy this time.


Cooking Oil

I recommend using ghee or coconut oil (not extra virgin). Both of these oils have a high smoking point and are very heat-stable. A tablespoon is all you need.


That’s all you need for this simple cooking process, but, if you are into sous vide and do it frequently, I recommend you invest in an immersion circulator which helps you turn any cooking dish into a sous vide water bath or maybe even get the actual sous vide water oven.


To summarize, this is all you need for cooking flat iron steak sous vide:

  • Flat iron steak
  • Salt (ideally kosher)
  • Freshly ground black pepper
  • Dutch oven
  • Candy/Oil Thermometer
  • Food-safe plastic bag*
  • Paper towels
  • For searing steak: Blowtorch or Skillet with 1 tbsp of coconut oil / ghee

If you haven’t yet cooked your steak, jump to Part 1 and do it. Or you can also go directly to Part 3 where you can find some recipes and sous vide cooking tips.


[nextpage title=”Part 4″ ]


Part 4: Pro Tips on Sous Vide

By now we have already made our sous vide flat iron steak in Part 1 and saw how to buy a quality steak and cooking utensils in Part 2.

This bit here is dedicated to cooking tips and recipes. Let’s check them out.


Tip 1: Seasoning

Choosing ingredients that are umami rich will give a particularly defined flavor to the completed flat iron steak.

For a good sous vide flat iron steak recipe, try mixing fish sauce, Worcestershire sauce and anchovy paste with blue cheese for a flavoursome marinade


Tip 2: Prolonged Cooking

As you saw in the table in Part 2, you only need 30 minutes to cook a 0.5inch steak. There I mentioned that your steak won’t overcook, if you continue cooking it, once that time runs out. If you keep going for another 30 minutes and maybe even an hour, you will notice your steak becoming even more succulent and tender. It happens because gentle heat breaks down tough connective tissue just like in slow cooking. Use this tip for tougher cuts like flat iron steak and make them restaurant-like!


Tip 3: Immersion Circulator

This awesome device converts any cooking container into a sous vide water bath and I highly recommend it for anyone using sous vide cooking method regularly. Not only they simplify the whole process dramatically (you don’t need to think about temperature adjusting at all), but they look cool too.


Tip 4: Sous Vide Cooking Bags

As already mentioned, I recommend you get highest quality sous vide cooking bags so to minimize the amount of chemicals leaching inside the steak. Look after this kind of stuff to keep you and your family healthy and looking good.



How to sous vide flat iron steak without immersion circulator?

Now you know. 🙂


Happy Steaks!



Ready To Enjoy That Juicy Tender Steak Every Single Time?

1. Get the Best Steak. Cooking steak to perfection is only 50% of success!
The other 50% come from great quality steak and I recommend you get those from here. Especially their grass-fed beef (they also have poultry, pork and loads of game!)