Cooked salad dressing is similar in appearance to mayonnaise, but it has a more tart flavor, while mayonnaise is richer and milder. Cooked dressing is made with little or no oil and with a starch thickener. It may be made in the kitchen or purchased already prepared. Formerly, it was little used in commercial kitchens because of its strong flavor and tartness, but now it is preferred to mayonnaise in some regions.
You will find in many cookbooks a great variety of dressings based on neither mayonnaise nor oil and vinegar. They include dressings based on sour cream and on fruit juice and yogurt (for fruit salads), and low-calorie dressings that appeal to the dieter. The important thing to remember is that these dressings should have well-balanced flavors with a pleasant tartness, and they should harmonize with and complement the salad with which they are served.