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How To Sous Vide Flat Iron Steak – Best Way

Last Updated on by SteakEat


Part: 2: Buying Guide & Utensils

Ok, we have just cooked our flat iron steak using sous vide technique in Part 1.

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.