Combine all of the ingredients in a clean jar and shake to emulsify.
¼ cup basil pesto, 2 tablespoons sour cream, 2 tablespoons mayonnaise, 2 tablespoons buttermilk, 2 tablespoons white wine vinegar
Adjust the thickness of the pesto dressing to your desired preference. For a thinner consistency, add more buttermilk or vinegar, perhaps a teaspoon at a time. To make it thicker, add more mayonnaise or sour cream.
This dressing should be stored in the refrigerator and is best within the first 3 to 5 days.
This creamy pesto salad dressing recipe makes three-quarters of a cup of dressing.