Mayonnaise as Beef Marinade: The Secret to Juicy, Flavorful Flat Iron Steak

If you’re looking for a flat iron steak marinade, here’s a tip you may not have tried yet: marinating flat iron steak in mayonnaise. It might sound unconventional, but mayonnaise is packed with ingredients that work beautifully as a marinade—fat, acidity, and seasoning potential. When paired with a BBQ rub, mayonnaise creates a flavorful crust while keeping your steak juicy on the grill.

In this post, we’ll cover:

• Why mayonnaise works as a beef marinade

• How to marinate a flat iron steak with mayonnaise and BBQ rub

• Step-by-step grilling instructions for the perfect steak

Why Mayonnaise Works as a Beef Marinade

Flat Iron Steak on cutting board

1. Locks in Juiciness
The oil in mayonnaise coats the meat, helping it retain moisture during grilling. This is especially important for lean cuts like flat iron steak.

2. Helps Tenderize
Mayonnaise has a mild acidity from vinegar or lemon juice, which gently tenderizes beef without overpowering its natural flavor.

3. Flavor Booster
Mayonnaise is a blank canvas that carries flavors well. When mixed with a BBQ rub, it helps spices stick evenly to the steak and forms a caramelized crust when seared.

4. Prevents Sticking on the Grill
The oil content also reduces the chance of the steak sticking to the grill grates—a big plus for backyard cooking.

How to Marinate Flat Iron Steak with Mayonnaise and BBQ Rub

Here’s a simple breakdown:

Ingredients:

• 2 flat iron steaks (about 1–1.5 lbs)

• 4 – 5  tablespoons mayonnaise for each steak

• 1–2 tablespoons BBQ rub (store-bought or homemade)

Flat Iron Steak topped with mayo

Steps:

1. Pat Dry: Use a paper towel to dry the steak. This helps the marinade cling better.

2. Coat with Mayonnaise: Spread mayonnaise evenly over both sides of the steak.

3. Add BBQ Rub: Sprinkle the BBQ rub on top and press it lightly so it sticks.

4. Marinate: Cover and refrigerate for at least 30 minutes (up to 4 hours for more flavor).

Flat Iron Steak covered in mayo and seasoning rub laying on titanium cutting board.

Mayonnaise coats, carries flavor, and tenderizes the steak while helping the BBQ rub stick and caramelize during grilling.

How to Cook flat Iron Steak.

Now it’s time to fire up the grill.

1. Preheat the Grill: Heat to medium-high, around 450°F.
2. Oil the Grates (Optional): Since mayonnaise already helps prevent sticking, this step is optional.
3. Grill the Flat Iron Steak:

• Place steak on the grill.

• Cook for 4–5 minutes per side for medium-rare, depending on thickness.

• Rest Before Slicing: Let the steak rest for 5 minutes, then slice against the grain.

Grilled Flat Iron Steaks laying on grill grates.

Final Thoughts

Using mayonnaise as a beef marinade isn’t just a kitchen hack—it’s a flavor enhancer and grilling shortcut. The flat iron steak comes off the grill with a juicy interior, a crust full of BBQ spices, and a restaurant-level finish.

If you’ve never tried it, this is your sign to give it a shot the next time you’re grilling.

Print Recipe

Flat Iron Steak Marinade - Mayonnaise

By Drew – Serves: 4

Prep Time: 5 minutes – Cooking Time: 15 minutes

If you’re looking for a flat iron steak marinade, here’s a tip you may not have tried yet: marinating flat iron steak in mayonnaise. It might sound unconventional, but mayonnaise is packed with ingredients that work beautifully as a marinade—fat, acidity, and seasoning potential. When paired with a BBQ rub, mayonnaise creates a flavorful crust while keeping your steak juicy on the grill.

Ingredients

• 2 flat iron steaks (about 1–1.5 lbs)
• 4 - 5  tablespoons mayonnaise for each steak
• 1–2 tablespoons BBQ rub (store-bought or homemade)

Instructions

1

Pat Dry: Use a paper towel to dry the steak. This helps the marinade cling better.

2

Coat with Mayonnaise: Spread mayonnaise evenly over both sides of the steak.

3

Add BBQ Rub: Sprinkle the BBQ rub on top and press it lightly so it sticks.

4

Marinate: Cover and refrigerate for at least 30 minutes (up to 4 hours for more flavor).

5

1. Preheat the Grill: Heat to medium-high, around 450°F.

6

2. Oil the Grates (Optional): Since mayonnaise already helps prevent sticking, this step is optional.

7

3. Grill the Flat Iron Steak:

8

Place steak on the grill.

9

Cook for 4–5 minutes per side for medium-rare, depending on thickness.

10

Rest Before Slicing: Let the steak rest for 5 minutes, then slice against the grain.

Notes

A BBQ Rub that is a sweet heat style is a good choice.