A vinaigrette is a salad dressing (or marinade) made from oil and either an acid, usually vinegar, or lemon juice. Salt, pepper, and other herbs, spices, and flavorings are added to customize the flavor. Traditionally, a simple vinaigrette is made from 3 parts oil to 1 part vinegar ratio, mixed into a stable emulsion. However, it can also be used to describe recipes with different proportions and for unstable emulsions which last only a short time before separating into layers. Different acids can be used such as citrus juices like lemon, lime, orange, or grapefruit. Various kinds of vinegar can be used including regular white vinegar, apple cider vinegar, rice vinegar, white balsamic vinegar, white wine vinegar, or red wine vinegar. Different oils can be used including olive oil, avocado oil, walnut oil, or sesame oil. In order to help the vinaigrette mix and combine together, it needs several teaspoons Dijon mustard to act as an emulsifier. This helps the oil blend into the vinegar without separating, to create a salad dressing.