In a separate small bowl—a glass or ceramic one works best so you can see what's happening—combine your olive oil mayonnaise, sour cream, white wine vinegar, sugar, salt, and pepper. Here's where older kids learn actual technique. Have them whisk slowly at first, then increase speed slightly. The goal is a smooth, pourable dressing with no lumps. It should fall from a spoon in ribbons, not plop in chunks. This usually takes about one minute of whisking. If it's too thick, whisk in a tablespoon of water at a time until you reach the right consistency.
Expert's Nutritional Tip: The emulsification happening in your bowl is where science meets flavor. The lecithin in egg yolks (in mayo) allows fat and water-based ingredients to stay suspended together. That's why your dressing coats evenly instead of separating. This is also why whisking speed matters—you're creating a stable emulsion that keeps vegetables fresher longer in storage.