When preparing a mayonnaise in summer keep the bowl as cold as possible. Beat up the yolks to a smooth consistency, add salt and white pepper, and oil. Beat up thoroughly, and by degrees add oil. When it begins to thicken add a few drops of vinegar. The total amount of vinegar to be used is two tablespoonfuls, and the proper time to stop adding oil, and to add drops of vinegar, is when the dressing has a glassy look instead of a velvet appearance. After a few trials almost any one can make a mayonnaise, as it is very simple.