This copycat version brings the iconic In-N-Out flavor straight to your kitchen. The balanced blend of tangy and sweet makes it perfect for burgers, fries, or any dish needing a flavor boost.
With just a handful of simple ingredients and 5 minutes of prep, you can recreate this restaurant-quality sauce that keeps everyone coming back for more.
Ingredients for In and Out Special Sauce
Nine simple ingredients recreate that iconic tangy, sweet flavor you know and love.
| Ingredient | Amount | Notes |
|---|---|---|
| Mayonnaise 🥚 | ½ cup | Full-fat for creaminess |
| Ketchup 🍅 | 2 tbsp | Classic American style |
| Sweet Relish 🥒 | 2 tbsp | Green or red works |
| Yellow Mustard 🟡 | 1 tsp | Classic prepared mustard |
| White Vinegar 💧 | 1 tsp | Balances the sweetness |
| Granulated Sugar 🍚 | 1 tsp | Adjust to taste preference |
| Garlic Powder 🧄 | ¼ tsp | Adds subtle depth |
| Onion Powder 🧅 | ¼ tsp | Complements the garlic |
| Paprika 🌶️ | ¼ tsp | For color and mild smokiness |
Mayo is the base here, so go for Hellmann’s or Duke’s—they’ve got the right texture and richness. The relish is non-negotiable for that signature crunch and sweetness. Heinz ketchup is my go-to, but any classic red ketchup works. Look for sweet relish near the pickles at the store (the bright green kind, not dill).
No relish? Finely chopped dill pickles plus a pinch of sugar gets you close. Swap yellow mustard for Dijon if that’s what’s in the fridge. The vinegar is key—don’t skip it, it cuts through the richness. Need more tang? Add an extra teaspoon of vinegar. Out of paprika? A dash of hot sauce works in a pinch.
This keeps in the fridge for about 1 week in a sealed jar. The flavors meld after a day, so it’s even better the next time. Stir before using—it’ll thicken up a bit in the cold. Perfect for burgers, but honestly, I put it on everything (fries, sandwiches, even as a dip for nuggets).
Why You’ll Love This Recipe
- Five-Minute Mix: I just dump everything in one bowl—mayo, ketchup, relish, mustard, vinegar—and stir. No cooking, no fuss.
- Tangy Sweet Balance: The sweet relish and vinegar give it that signature In-N-Out zing I can’t resist.
- Burger Night Hero: Slap it on burgers, use it for fries, or even as a sandwich spread. Honestly, it works everywhere.
- Pantry Staples Only: I always have these ingredients on hand, so I can make it anytime without a last-minute store run.
Step-by-Step Instructions for In And Out Special Sauce
This comes together in minutes with no cooking required—just mix and enjoy.
Step 1: Combine the Base Ingredients
In a medium bowl, whisk together the ½ cup mayonnaise and 2 tablespoons ketchup until completely smooth. I like to use a fork for this—it helps break up any lumps in the mayonnaise and ensures both ingredients blend seamlessly.
The mayonnaise creates that signature creamy base, while the ketchup adds the tangy sweetness that defines this sauce. You’ll notice the mixture lighten slightly in color as they combine.
Step 2: Add the Sweet and Tangy Elements
Stir in the 2 tablespoons sweet relish, 1 teaspoon yellow mustard, and 1 teaspoon white vinegar. The relish adds tiny bursts of sweetness and texture, while the mustard and vinegar balance it with a sharp tang.
I always use green relish for that classic look, but red works just as well. Mix until you see the relish evenly distributed throughout—this usually takes about 30 seconds of steady stirring.
Step 3: Sweeten and Season the Sauce
Add the 1 teaspoon granulated sugar and stir until it fully dissolves into the mixture. This step rounds out the flavors, taking the edge off the vinegar and mustard while enhancing the sweetness of the relish.
Now sprinkle in the ¼ teaspoon garlic powder, ¼ teaspoon onion powder, and ¼ teaspoon paprika. These spices add depth without overpowering the sauce. The paprika also gives it that subtle smoky note and a hint of color.
Step 4: Let the Flavors Meld
Cover the bowl and let the sauce sit at room temperature for at least 10 minutes. This short rest allows all the flavors to meld together, transforming it from a simple mixture into something truly special.
Give it a final stir before using. The sauce should be smooth, slightly thick, and flecked with bits of relish. Taste and adjust the sugar if you’d like it a touch sweeter—some prefer it a little more tangy, others a bit sweeter.
Pro Tips For Making In And Out Special Sauce
- Chill the Sauce: After mixing, refrigerate the sauce for at least 30 minutes—I learned this the hard way when my first batch tasted flat because the flavors hadn’t melded.
- Drain the Relish: Press the sweet relish in a fine-mesh strainer for 10 seconds to remove excess liquid, or your sauce will be watery and separate over time.
- Skip the Cheap Mayo: Use full-fat, high-quality mayonnaise like Hellmann’s or Duke’s; the low-fat versions make the sauce thin and bland.
- Stir, Don’t Whisk: Fold everything together gently with a spoon instead of whisking—it keeps the texture creamy rather than aerated and foamy.
Common Mistakes When Making This Recipe
Skipping the Resting Time
I always let my sauce rest for at least 10 minutes after mixing. This step lets the spices bloom and the flavors meld together. Without it, the sauce tastes flat and one-dimensional. 💡
Overmixing the Ingredients
Stir just until everything is combined—about 30 seconds for the relish. Overmixing breaks down the relish pieces, leaving you with a smooth, boring sauce instead of that signature texture with little bursts of sweetness.
Using Low-Fat Mayo
Full-fat mayonnaise like Hellmann’s or Duke’s is essential for the right creaminess. Low-fat versions make the sauce thin and watery, and they just don’t deliver that rich, velvety mouthfeel you expect from this recipe.
Skipping the Vinegar
The 1 teaspoon white vinegar might seem small, but it’s crucial for balancing the sweetness. Without it, the sauce can taste cloying. If you’re out of white vinegar, apple cider vinegar works in a pinch, but don’t leave it out entirely.
Adding Too Much Sugar
Start with the 1 teaspoon granulated sugar and taste before adding more. This sauce should be tangy first, sweet second. Too much sugar overpowers the other flavors and turns it into a dessert topping.
Storing Improperly
Always transfer the sauce to an airtight container before refrigerating. Left uncovered, it absorbs fridge odors and dries out. It keeps for about 1 week, but I doubt it’ll last that long once you try it! 🔥
Nutrition Facts
Frequently Asked Questions
Can I use a different type of relish?
Green sweet relish is traditional, but red works too. For a tangier twist, try dill relish—just add an extra ½ teaspoon sugar to balance the flavor.
How long can I store this sauce?
In an airtight container in the fridge, it stays fresh for up to 1 week. The flavors deepen after 24 hours, making it taste even better the next day.
What if I don’t have white vinegar?
Apple cider vinegar is the best substitute. Use the same 1 teaspoon amount—it adds a slight fruitiness but keeps the tangy balance. Avoid balsamic, as it’s too strong.
Can I make this ahead for a party?
Prepare it up to 2 days in advance for optimal flavor. Stir well before serving, as the ingredients may separate slightly in the fridge.
- Prune Sauce Recipe for Pork: Rich and Fruity Glaze for Roasts - September 25, 2026
- Fries Dip Sauce Recipe: Creamy Garlic Herb Blend for Perfect Pairing - September 25, 2026
- Firecracker Shrimp Sauce Recipe: Spicy-Sweet Dipping Delight - September 25, 2026