Ingredients:

  • 1/2 cup Mayonnaise (full-fat preferred)
  • 2 Tablespoons Ketchup
  • 2 Tablespoons Sweet Pickle Relish
  • 1 teaspoon Yellow Mustard (classic American style)
  • 1/2 teaspoon White Vinegar or Pickle Juice
  • 1/2 teaspoon Granulated Sugar (optional)
  • Pinch Fine Sea Salt, or to taste
  • Pinch Freshly Ground Black Pepper, or to taste

Instructions:

  1. Measure the mayonnaise, ketchup, sweet relish, yellow mustard, and white vinegar (or pickle juice) into a small mixing bowl.
  2. Add the granulated sugar (if using), sea salt, and black pepper to the wet ingredients.
  3. Use a whisk or spatula to vigorously combine all ingredients until the mixture is uniform in color and texture, ensuring no streaks of mayonnaise remain.
  4. Transfer the sauce to an airtight container. Refrigerate for a minimum of 2 hours, or ideally overnight, to allow the flavors to deepen and meld completely.
  5. After chilling, taste the spread. Adjust the salt/pepper as needed, or add a slight dash more vinegar if a tangier profile is desired.
  6. Store the finished In N Out Sauce in the refrigerator until ready to serve on burgers or fries.