How to Marinate Flat Iron Steak Using Simple Marinades & Rubs

Last Updated on by SteakEat

how-to-marinate-flat-iron-steak-simple-way-recipesFlat ion steak tender is often as tender as the best fillet. This is especially so if it has been well butchered as a skilled butcher will remove tough connective tissue as the steak is prepared.

However, all steak benefits from being made more tender, especially if you are one of those people who enjoy their steak medium to well done as longer exposure to heat will toughen up the fibers in the meat.


Tenderize with Enzymes

Before you consider using a meat tenderizer, you need to know that naturally occurring compounds will have a tenderizing effect on your flat iron steak.

Found in fruit acids, vinegars and enzymes (e.g. kiwi), they are a natural way of breaking down muscle structures leading to more tender meat.

Marinades are a perfect way of applying enzymes to flat iron steaks.

The best marinades should only be used for two hours. If you use them for longer, you are risking over-marinating your steak – the enzymes can have the opposite effect on the surface of the meat and make it tough.

Acidic fruits such as citrus fruits, pineapples or kiwi fruit are particularly rich in these enzymes although most fruits can be used as the basis for an excellent tenderizing marinade.

Vinegars are also make good bases for marinades as does buttermilk.

Pineapple needs to be used carefully as it contains an enzyme called Bromelain which can turn your flat iron steak to mush if used for too long.

Puree fruits such as pineapple or kiwi and simply juice oranges, lemons or limes to add to a marinade to ensure your steak is tenderized.


Lime Marinade Recipe

The citric acid in lime juice is a perfect base for a marinade as it is rich in the enzymes that break down muscle tissue and tenderize it.


  • ¼ cup fresh lime juice, three or four limes
  • 1 orange juiced
  • 2 cloves of garlic, crushed
  • 3 tablespoons balsamic vinegar
  • ½ cup olive oil
  • Salt and pepper
  • 1½ pound of flat iron steak


  • Place a large plastic bag in a shallow baking tray or a plate
  • Combine the lime juice, garlic, orange juice, balsamic vinegar and olive oil with the salt and pepper in the bag
  • Add the steak and turn to ensure it is evenly coated in the marinade
  • Marinate for 1-2 hours at room temperature or place in the fridge for overnight marinating (can be done fine with this acid-based marinade; enzyme-based marinades will be too aggressive for such a long period)
  • Remove and bring the steak to room temperature 40 minutes before cooking in your favorite way


Red Wine Marinade Recipe

One of the classic marinades that can be used with flat iron steak is a red wine marinade as follows:


  • 2 cups red wine
  • 1 small onion diced
  • 2 teaspoons of orange zest
  • 2 sprigs of fresh rosemary
  • 2 tablespoons redcurrant jelly
  • 1 teaspoon salt
  • 1 teaspoon black pepper


  • Combine the red wine, onion, orange zest and redcurrant jelly in a glass or plastic bowl
  • Bruise the rosemary with the back of a knife and add to the bowl
  • Pour the marinade into a sealable plastic and add your flat iron steak
  • Place the bag in the refrigerator for one to two hours
  • Remove the steak from the bag and put to one side at room temperature 40 minutes before cooking


Marinating with Dry Rub Spices

Conventional marinating adds several hours to the time it takes to prepare a good flat iron steak.

This time can be cut down by using dry rub spices. Flat iron steaks are already quite tender due to the way your butcher prepares the cut so do not require as much tenderizing as other cheaper cuts of steak.

This means it is possible to prepare a flat iron steak dry rub recipe style. Make sure to not overcook this cut. I recommend not exceeding medium-rare level of doneness for best results.

If you are into well-done steak, try using low & slow cooking in the oven. Quickly sear the steak on the stove (2 minutes per side max) and place it in the oven with the inside temperature not exceeding 120C / 250F. It will take more time to finish, but the result is well worth it.

Generally, whole spices should be toasted in a warm pan to release their oils before being ground in a mortar and pestle or a spice grinder.

They can be applied directly to your flat iron steak which will then release the mix of flavors you have chosen when you cooked it.

Tuscan Rub
  • Toast one table spoon of fennel seeds in a hot pan until they become aromatic
  • Grind the fennel seeds in a spice grinder or mortar and pestle
  • Combine with 6 tablespoons of dried basil, 3 tablespoons garlic powder, 3 tablespoons coarse salt, 2 tablespoons dried rosemary, 2 tablespoons dried oregano
  • Rub the Tuscan rub into both sides of your flat iron steak and put the steak to one side, to come up to room temperature before cooking
  • Cook your steak using your preferred skillet, broiler or grill method for a rich Italian flavor



All flat iron steak cooking methods:

Return to main pagehow to cook flat iron steak.

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