Foster Sauce Recipe: Tangy-Sweet White BBQ Tradition

White BBQ sauce is a Southern tradition that deserves a place in every kitchen for its unique tangy-sweet profile.

This version balances mayonnaise, vinegar, and a touch of horseradish for that signature creamy kick that elevates chicken, fries, or sandwiches.

Ingredients for Foster Sauce

Classic Southern flavors come together in this tangy-sweet white sauce for a unique twist.

The mayonnaise base is non-negotiable—Duke’s or Hellmann’s deliver the right creaminess and stability. Apple cider vinegar adds the signature tang, but white vinegar works in a pinch (just reduce by a tablespoon). Horseradish is the secret weapon here; look for prepared horseradish in the refrigerated section near the pickles, not the shelf-stable jars which lack freshness and punch.

Need to adjust the heat? Reduce horseradish to 1 tbsp for a milder kick or add a dash of hot sauce for extra spice. No apple cider vinegar? White wine vinegar at a 1:1 ratio maintains the acidity. For a smoother texture, whisk the sauce vigorously or pulse briefly in a blender—this helps the horseradish distribute evenly without clumping.

This sauce keeps beautifully in the fridge for up to 2 weeks in an airtight container. The flavors meld and deepen over time, so making it a day ahead is ideal. Stir well before each use, as the ingredients may separate slightly.

Step-by-Step Instructions for Foster Sauce

This tangy white sauce comes together quickly with precise mixing and resting for optimal flavor development.

Step 1: Combine the Wet Base Ingredients

In a medium mixing bowl, whisk together the 1.5 cups Mayonnaise and 0.5 cup Apple Cider Vinegar until completely smooth and emulsified. The vinegar’s acidity will initially cause the mayonnaise to tighten slightly, but continue whisking until it returns to a creamy consistency.

This base creates the signature tangy foundation of the sauce. I use full-fat mayonnaise for its rich texture, which balances the sharp vinegar perfectly. The mixture should have no visible separation between the two components before proceeding.

Step 2: Incorporate the Sweet and Pungent Elements

Add the 2 tbsp Granulated Sugar, 2 tbsp Prepared Horseradish, and 1 tbsp Dijon Mustard to the mayonnaise mixture. Whisk vigorously for 30-45 seconds until all ingredients are fully integrated and the sugar begins to dissolve.

The horseradish will add a subtle heat that builds slowly, while the sugar tempers the acidity. The Dijon mustard deepens the flavor profile without overpowering the delicate balance. You should see small bubbles forming as you whisk, indicating the sauce is properly emulsifying.

Step 3: Season and Brighten the Mixture

Sprinkle in the 1 tsp Garlic Powder, 1 tsp Onion Powder, 0.5 tsp Salt, and 0.5 tsp Black Pepper. Whisk for another 20-30 seconds until all dry ingredients disappear into the sauce.

These seasonings enhance the savory notes without overwhelming the primary flavors. The garlic and onion powders provide depth while the salt and pepper create the foundation of the sauce’s character. Taste at this point and adjust salt if needed, though the flavors will meld further during resting.

Step 4: Finish with Citrus and Final Emulsification

Add the 1 tbsp Lemon Juice and whisk for a final 30 seconds. The fresh citrus brightens the entire mixture and ties all the flavors together. The sauce should now have a consistent, slightly thick texture with a glossy appearance.

This last addition is crucial as it lifts the rich flavors and adds a fresh dimension to the finished product. The lemon juice also helps stabilize the emulsion, preventing separation during storage.

Step 5: Rest and Chill for Optimal Flavor

Transfer the sauce to an airtight container and refrigerate for at least 2 hours (overnight is ideal). This resting period allows the flavors to fully meld and the horseradish to mellow slightly.

The sauce will thicken slightly as it chills. Before serving, give it a good stir to redistribute any settled ingredients. The finished product should have a smooth, creamy texture with a balanced sweet-tangy-spicy profile that’s perfect for dipping or basting.

Essential Equipment for Great foster sauce

Mixing Bowls

I always use a medium stainless steel mixing bowl for this sauce. The smooth surface makes whisking easier and helps prevent ingredients from sticking. A 2-quart bowl gives you plenty of room to whisk vigorously without splashing.

Whisk Selection

A balloon whisk is my go-to tool here—it incorporates air beautifully while breaking up any clumps of horseradish. The curved shape fits perfectly in the bowl’s contour. I prefer OXO’s 11-inch whisk for its comfortable grip and durability. 💪

Measuring Tools

Precise measurements matter for this sauce’s balance. I rely on a set of stainless steel measuring cups and tablespoons for accuracy. Pyrex makes excellent glass measuring cups that won’t absorb odors or stains from the vinegar.

Storage Containers

For storage, glass mason jars with airtight lids work perfectly. I like 16-ounce wide-mouth jars because they’re easy to fill and clean. The glass won’t react with the acidic ingredients, preserving the sauce’s fresh flavor.

Optional Blending

If you prefer an ultra-smooth texture, a mini food processor or immersion blender works wonders. I use my Cuisinart mini-prep for small batches. Just pulse 3-4 times to blend without over-processing.

Cleanup Essentials

A silicone spatula helps scrape every last bit of sauce from the bowl. I keep a damp cloth nearby to quickly wipe up any splashes from the vinegar or horseradish. This sauce cleans up easily with warm, soapy water. ✨

Frequently Asked Questions