In a small mixing bowl, add sour cream, mayonnaise, and whole milk. Whisk together until smooth and fully combined.

Add white wine vinegar, Worcestershire sauce, garlic powder, black pepper, and kosher salt. Whisk again until fully incorporated.

Add crumbled blue cheese and stir gently using a spoon or silicone spatula, breaking up some of the chunks if you prefer a smoother dressing, or leaving them as-is for a chunkier texture.

Taste and adjust seasoning if needed. If the dressing is too thick, stir in a little more milk, 1 teaspoon at a time, until it reaches your desired consistency.

Cover and refrigerate for at least 30 minutes to allow flavors to meld. Stir before serving.