In-N-Out Burger Sauce

In-N-Out Is a burger chain in several western states.  It is known for their juicy burgers slathered in their special sauce with optional (though I always get mine this way) grilled onions, called “animal style”.

Whenever I find myself in Nevada, California, and Arizona,  In-N-Out burger restaurants are at the top of the list for where we go to eat.  It’s Americana at its best…an ooey, gooey, cheesy, oniony (is that a word? It is now…),

After many trials and errors trying to replicate the “spread”, I think I finally came up with a sauce as close to the real thing as possible.  It’s not just a mixture of ketchup, mayo and relish like most people think.  It’s also not regular thousand island dressing.  This is my version of the sauce.  Adding a bit of apple cider vinegar, sugar and a pinch of onion powder to the K-M-R mixture did the trick.  Refrigerate the mixture for a good 30 minutes before assembling your burgers to allow the flavors to meld.

I also include a recipe for caramelized onions to go on top of your burgers.  It won’t be “animal style” without the sweet, gooey caramelized onions slathered on top of your burger.

Add your favorite cheese (use American cheese for a true In-N-Out replica) and voila! Homemade In-N-Out Burgers right at home.  Oh yeah, you mustn’t forget the pickles, sliced tomato and crisp iceberg lettuce.  Oh man, I want a cheeseburger now!

Give it a try and let me know what you think of it.  I think you’ll like it. 🙂

In-N-Out Burger Sauce


  • 3/4 cup plus 2 tablespoons real mayonnaise
  • 1/3 cup ketchup
  • 3/4 cup sweet pickle relish
  • 1 tablespoon sugar
  • 1 tablespoon apple cider vinegar
  • 1/4 teaspoon onion powder


1.  Mix all of the ingredients together in a small bowl.

2.  Refrigerate for 30 minutes; set aside until ready to assemble the burgers.

This makes enough for 4-6 burgers.  This sauce is also great on French fries, in a grilled ham and cheese sandwich, and even as a salad dressing.


“Animal Style” Caramelized Onions


  • 6 large onions, diced (use sweet onions, like Vidalia or Walla Walla, if you can find them, otherwise yellow Spanish onions will work well)
  • 2 tablespoons vegetable oil
  • 8 tablespoons water (you can use beef stock instead for a richer flavor)
  • 1 tablespoon salt
  • 1 tablespoon sugar


1.  Heat the oil in a large pan over medium-high heat.  Add the onions, salt and sugar to the pan.

2.  Reduce the heat to medium-low, cooking the onions and stirring occasionally until they begin to brown, about 20 minutes.

3.  Add four tablespoons of water to the pan, stir, and cook until the onions are dried down and the water evaporates.

4.  Add four more tablespoons of water to the pan, repeating step 2 above. The onions should be a dark brown (not burnt) and soft.  Remove the onions from the pan; set aside until you’re ready to assemble the burgers.

Total cooking time for the onions varies, but it should take about 40-45 minutes of cooking to get soft, sweet, dark brown onions.

This recipe makes enough caramelized onions for 4-6 burgers.


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  1. Albert J. Taitano says:

    In-N-Out Burger Sauce … just wondering, on your first bullet … 3/4 cup plus 2 tablespoons real mayonnaise. 3.4 cup of what … water? I am not sure what 3/4 cup stood for. Anyway, Ms Annie thanks for sharing your recipes … I am in Korea and I do enjoy cooking Chamorro Style … staying away from Haolie foods … I do Korean foods, but seldom … island style meals are the best. Al

    • Hafa Adai, Al! My recipe calls for “3/4 cup plus 2 tablespoons real mayonnaise.” What this means is 3/4 cup of mayonnaise PLUS an additional 2 tablespoons of mayonnaise. Or, 3/4 cup of mayo + 2 tablespoons of mayo.

      So, where in Korea are you? I was stationed in Seoul several years ago…lived there for 3 years with my family. We loved it there, and miss it!

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