Mix the Base. In a medium-sized mixing bowl, combine the mayonnaise, apple cider vinegar, and lemon juice. Whisk these ingredients together until they are well incorporated. The tangy foundation of the white BBQ sauce is starting to take shape.
Add the Flavors. Next, add the prepared horseradish, Worcestershire sauce, garlic powder, onion powder, black pepper, salt, and cayenne pepper (if desired) to the mixing bowl. These ingredients will infuse the sauce with layers of flavor, providing a delightful kick.
Whisk to Perfection. Using a whisk or spoon, vigorously stir the mixture until all the ingredients are thoroughly combined. The sauce should become smooth and creamy, with a consistent texture throughout. Take a moment to savor the tantalizing aroma that begins to fill the air.
Adjust the Flavor. Give the sauce a taste and adjust the seasonings to suit your preferences. Feel free to add more vinegar for tang, horseradish for heat, or any other ingredient to enhance the flavors according to your liking. Remember, the beauty of this white BBQ sauce lies in its versatility.
Let It Rest. Cover the mixing bowl with plastic wrap or transfer the sauce to an airtight container. Allow it to rest in the refrigerator for at least 2 hours, or preferably overnight. This resting period will give the flavors a chance to mingle and intensify, resulting in an even more delectable sauce.