This smash burger sauce became my go-to condiment the first summer I tried making smashed patties at home. I was chasing the crisp, caramelized edges of a diner burger and realized the right sauce makes the difference between a good sandwich and a memorable one. I first put this mix together on a slow Sunday when I had a jar of mayonnaise, a squeeze of ketchup, and a lonely spoonful of relish. The combination of creamy fat, bright mustard, and sweet-sour relish created a perfect counterpoint to a charred beef patty and soft potato bun. Family and friends kept reaching for more; it vanished faster than the burgers themselves.

What I love most about this formula is how balanced it is straight away: creamy and rich from mayonnaise, tangy from mustard, sweet and briny from ketchup and relish, with a background warmth from paprika and aromatics from garlic and onion powder. Texture matters here — the tiny pickle bits in the relish give small bursts of acidity and crunch that play beautifully against a tender, flat-cooked patty. I often make a double batch before a cookout because it stores well and improves after a short chill when the flavors meld.

Over time I refined the seasoning ratios to suit a classic smashed-burger profile: enough mustard to cut the richness, a touch of paprika for color and mild smokiness, and a careful pinch of salt and pepper to bring everything into focus without overwhelming the beef. This is the kind of condiment that elevates simple ingredients into something you look forward to spooning onto every sandwich. If you want to tweak heat, a few drops of your favorite hot sauce do wonders without changing the sauce’s essential character.

Ingredients

• Mayonnaise (1/2 cup): Use a full-flavored mayonnaise for the creamiest mouthfeel. I prefer a higher-egg content brand for richness; Duke's or Hellmann’s work well. For lower-fat or vegan needs, choose a quality alternative but expect a lighter mouthfeel.
• Ketchup (2 tablespoons): Adds sweetness and red color. Look for a tomato-forward ketchup without pronounced vinegar if you want a milder tang; a thicker brand helps the sauce cling to burgers.
• Yellow mustard (1 tablespoon): Provides sharp acidity and a hint of spice — classic American yellow mustard is ideal for the familiar diner flavor.
• Pickle relish (1 tablespoon): Sweet or dill relish both work, but sweet relish gives the traditional smash-burger profile with small crunchy pickle pieces for texture.
• Garlic powder (1/2 teaspoon) and Onion powder (1/2 teaspoon): These dried aromatics add savory depth. Use fresh-grind powders for the best intensity; if using garlic paste, reduce quantity accordingly.
• Paprika (1/2 teaspoon): For color and a touch of warm, sweet pepper note. Smoked paprika adds subtle smokiness if you want more char flavor.
• Salt (1/4 teaspoon) and Black pepper (1/4 teaspoon): Small but essential — salt amplifies flavors and pepper adds a mild bite.
• Hot sauce (few drops): Optional. A couple drops of Tabasco or your favorite hot sauce brightens the mix without making it spicy; adjust to taste.

Instructions

Step 1 — Gather equipment: Select a medium mixing bowl, a whisk or sturdy spoon, measuring spoons and cups, and an airtight jar or squeeze bottle for storage. Having everything pre-measured keeps the mixing smooth and prevents over-seasoning. Step 2 — Combine base ingredients: Measure 1/2 cup mayonnaise, 2 tablespoons ketchup, 1 tablespoon yellow mustard, and 1 tablespoon pickle relish into the bowl. Add the thicker items first and spoon the thinner ingredients on top so they incorporate evenly when whisked. Step 3 — Season and whisk: Sprinkle in 1/2 teaspoon garlic powder, 1/2 teaspoon onion powder, 1/2 teaspoon paprika, 1/4 teaspoon salt, and 1/4 teaspoon black pepper. Whisk briskly until the mixture is glossy and homogenous, about 20 to 30 seconds. Taste for balance — if the sauce tastes flat, a tiny pinch more salt will lift it. Step 4 — Taste and adjust: Sample a small dollop on the back of your hand or a spoon. For more sweetness add a touch more ketchup, for extra tang a little more mustard, and for heat add a few drops of hot sauce. Adjust one element at a time and whisk between additions to keep the balance. Step 5 — Chill and serve: Transfer the sauce to an airtight jar or squeeze bottle and refrigerate for at least 30 minutes to let flavors meld. Stir or shake once more before serving and use within 5 to 7 days. The sauce will thicken slightly as it chills.

Storage Tips

Store the sauce in an airtight jar or squeeze bottle in the coldest part of your refrigerator, not the door, to maintain steady temperature. Use within 5 to 7 days; label the container with the date you made it. If you notice water separation, stir vigorously — a short rest will often allow the emulsion to rebind. Avoid double-dipping when serving to keep the batch fresh longer; pour a small amount into a serving bowl if you expect heavy use.

Ingredient Substitutions

If you need to accommodate dietary preferences, try vegan mayonnaise in place of regular mayo — the sauce will be slightly lighter but still pleasing. For lower sugar, use a reduced-sugar ketchup or cut the ketchup to 1 tablespoon and add a pinch of smoked paprika to retain depth. Swap sweet relish for dill relish for a tangier profile; reduce the relish slightly if you want less crunch. If you prefer a spice-forward version, replace 1/4 teaspoon paprika with 1/4 teaspoon cayenne, but add gradually to avoid overwhelming the balance.

Serving Suggestions

Use this sauce on smashed beef patties with American cheese on soft potato buns for a classic pairing. It also elevates grilled chicken sandwiches, crispy fish sandwiches, and roasted vegetable wraps. Spoon a dollop on fries or onion rings as a decadent dip. Garnish burgers with shredded iceberg lettuce and thinly sliced red onion to add crunch and brightness that contrasts the rich sauce.

Cultural Background

This style of burger sauce draws from American diner and fast-casual traditions where simple emulsions — mayonnaise, ketchup, and mustard — were combined with pickled elements to create a tangy, comforting spread. Variations of this spread have long been used across the United States as an accessible way to add complexity to sandwiches without requiring elaborate ingredients.

Seasonal Adaptations

In summer, brighten the sauce with a teaspoon of finely chopped fresh dill or chives and use fresh cornmeal buns for a cookout twist. In fall and winter, consider a pinch of ground mustard powder and smoked paprika for deeper, warming flavors. For holiday sliders, fold in a tablespoon of cranberry relish to pair with richer meats like turkey or lamb.

Meal Prep Tips

Prepare a batch at the start of the week and portion it into small jars for lunches and meal boxes. A squeeze bottle is handy for quick assembly of sandwiches and prevents excess contact with utensils, keeping the remainder fresher. If you plan to pack sandwiches, keep sauce in a separate container until ready to eat to avoid soggy bread.

End on a simple note: this little sauce is more than the sum of its parts — it’s the finishing touch that turns a homemade burger into an occasion. Make it, tweak it, and make it your own. Share jars with friends and you’ll likely get the same requests I do: one more bottle before the next grill night.