Copycat In N Out Sauce Recipe: Secret Spread for Burger Perfection

I’ve spent years perfecting this copycat version of the famous In-N-Out spread. The secret lies in the precise balance of sweet relish and tangy mustard.

This perfect sauce transforms any burger into a West Coast classic. With just 5 minutes and common pantry staples, you’ll have a condiment that rivals the original.

Ingredients for Copycat in N Out Sauce

Eight pantry staples blend into that iconic West Coast spread everyone loves.

The relish is non-negotiable here. Heinz sweet relish is the closest to what In-N-Out uses (the green kind, not the neon stuff). Mayonnaise needs to be full-fat—Hellmann’s or Duke’s give you that perfect creamy base. Most grocery stores carry all of this in the condiment aisle. If you’re making a big batch, Costco-size mayo is your friend (worth the splurge).

No sweet relish? Finely chopped bread and butter pickles plus a pinch of sugar gets you close. Short on mustard? Dijon at half the amount works, but it’ll be sharper. The vinegar balances the sweetness—apple cider vinegar if that’s what you’ve got. Skip the garlic powder? Fresh minced garlic at double the amount, but let it sit 5 minutes first.

This keeps 1 week in the fridge in a sealed jar. The flavors meld after 24 hours, so make it ahead if you can. Freezing’s not ideal (separates weird), but it’ll last 1 month if you must.

Step-by-Step Instructions for Copycat In N Out Sauce

Here’s the method that delivers that iconic spread with perfect balance every time.

Step 1: Combine the Creamy Base Ingredients

In a medium mixing bowl, I start by adding the 0.5 cup Mayonnaise and 2 tbsp Ketchup. These two form the creamy foundation of the sauce. Use a whisk to combine them thoroughly until the mixture turns a uniform pale orange color with no visible streaks.

Here’s the thing—full-fat mayonnaise is non-negotiable. The richness and thickness it provides can’t be replicated with low-fat versions. You’ll notice the texture becomes smooth and slightly glossy as you whisk, which is exactly what you want for that authentic spread consistency.

Step 2: Incorporate the Tangy and Sweet Elements

Next, add the 2 tbsp Sweet Relish and 1 tbsp Yellow Mustard to the bowl. The relish brings that signature sweetness with tiny bits of texture, while the mustard adds the sharp tang that makes this sauce so addictive.

Whisk again for another 30-45 seconds until everything is fully integrated. I’ve found that green relish gives the most authentic flavor, but yellow works in a pinch. The mixture should now have a slightly chunkier appearance from the relish, but still maintain its creamy base.

Step 3: Add the Finishing Touches for Depth

Now for the flavor boosters: add the 1 tsp White Vinegar, 0.25 tsp Garlic Powder, 0.25 tsp Onion Powder, and 0.25 tsp Paprika. The vinegar brightens all the other flavors, while the powders add subtle depth without overpowering.

Whisk for a final 1 minute until completely smooth. The sauce will have a vibrant, slightly reddish hue from the paprika. Taste and adjust if needed—though with these exact measurements, it should be spot-on to the original.

Step 4: Rest and Serve for Optimal Flavor

Transfer the sauce to an airtight container and let it rest in the refrigerator for at least 1 hour. This resting period allows all the flavors to meld together beautifully. I know it’s hard to wait, but the difference is noticeable.

When ready to use, give it a good stir. The sauce will keep in the fridge for up to 5 days, and the flavors actually improve slightly over time. Spread it on burgers just before serving for that true In-N-Out experience, or use it as a dip for fries. Each batch makes enough for about 4 burgers.

Best Sauces and Condiments for This Recipe

Classic Burger Pairings

This spread transforms any burger into a West Coast masterpiece. I love it on double-double cheeseburgers with lettuce wrap for that authentic In-N-Out experience. The creamy texture balances perfectly with crisp vegetables.

Fry Dipping Sauce

Use it as a dipping sauce for crinkle-cut fries or animal-style fries. The tangy sweetness cuts through the saltiness beautifully. I always make extra for fries—it disappears faster than the burgers do. 🔥

Breakfast Twist

Try it on breakfast sandwiches with scrambled eggs and American cheese on an English muffin. The vinegar and relish wake up the flavors in a way plain mayo can’t. A little goes a long way at breakfast time.

Grilled Cheese Elevation

Spread a thin layer on sourdough bread before adding cheese for a next-level grilled cheese. The mustard and relish add complexity that pairs especially well with sharp cheddar or pepper jack.

Hot Dog Topping

Drizzle over all-beef hot dogs instead of plain mustard or ketchup. It adds that signature In-N-Out flavor to ballpark favorites. Kids especially love this—it’s sweeter than traditional hot dog toppings.

Veggie Burger Boost

This sauce brings life to black bean burgers or portobello mushroom burgers. The creaminess helps hold veggie patties together while adding that umami depth meat eaters crave. 💛

Frequently Asked Questions