Learn how to make a vinaigrette dressing. Vinaigrette is a cold emulsified sauce made of red wine vinegar (or sometimes citrus juice), salt, pepper and vegetable oil, often flavored with herbs, spices, and other ingredients. There are many ways to prepare a perfect vinaigrette recipe, but a basic recipe is to slowly add 3 parts of oil at room temperature to 1 part of seasoned (salt and pepper) vinegar until it emulsifies into a smooth sauce. Herbs are sometimes added to enhance flavor. The addition of a small amount of mustard can help keep the oil and acid in an emulsion. In France, the vinaigrette is often prepared once a week in large quantities.