Stir the yolk of one egg in a bowl for one minute, then add oil drop by drop, stirring all the time; when once the oil and egg have thickened, and taken an opaque creamy consistency, the oil may be put in more freely. Yet always be careful to see it well blended before adding more.

When it gets very thick, add a few drops of vinegar, then more oil, till you have as much as you require; the vinegar must depend on individual taste; half a gill of vinegar is usually enough for half a pint of oil. Add salt and pepper last; many mix a teaspoonful of dry mustard with the egg at starting, but although a pleasant addition, it does not belong to mayonnaise proper, but to tartar sauce.

N. B. - This sauce can be made more surely when bowl, egg and oil are ice cold; in warm weather make it in a cool room.