It has been found that the oil may be added more rapidly if the egg is acidified before mixing it with the oil. [Footnote 66: This is due to the fact that the acid reacts with the albumin of the egg to form a kind of salt which hydrates and takes up water from the mixture. The more water that can be taken out of an emulsion in the form of hydrates, the more easily will an emulsion be formed.] The addition of boiling water to the mixture after the egg and oil have been blended, prevents the oil from separating from the other ingredients.
[Illustration: FIGURE 63—THE COMPOSITION OF BUTTER AND OTHER FAT-YIELDING
FOODS (Revised edition)]
If desired, the whole egg may be used in place of the egg yolks. In case this substitution is made, all the ingredients other than the egg should be doubled in quantity, since 1 whole egg will emulsify 2 cupfuls of oil.
The flavor of refined corn, cottonseed, or peanut oil is mild and pleasing. These oils have less flavor than olive oil but are as nutritious. Their use lessens the cost of Mayonnaise Dressing. After opening a bottle of vegetable oil, it should be kept in a cold place. If it is rancid, it should not be used in salad dressing.
If Mayonnaise Dressing is made successfully, it is thick and smooth. If the dressing is thin and curdled, the oil has been added too quickly, i.e. it has not been emulsified.
To remedy Mayonnaise that has curdled, beat the yolk of an egg slightly, then add the dressing to it gradually, beating constantly.
Mayonnaise Dressing may be varied by the addition of chili or celery sauce, chopped hard-cooked eggs, chopped parsley, pimentos, and green peppers.
QUICK MAYONNAISE DRESSING [Footnote 67: Adding the entire quantity of oil at one time and mixing it with hot paste may seem an unusual procedure for making an oil dressing. The fact that the method is successful may be explained as follows: Mixing the acid with the egg forms a salt which hydrates the mixture, and thus aids in making favorable conditions for emulsifying the oil as explained in the footnote of a previous page. The starch paste also takes up water from the mixture. This makes it possible to emulsify the oil easily, and also to make a stable emulsion.]
2 egg yolks or 1 whole egg 2 tablespoonfuls vinegar 2 tablespoonfuls lemon juice 1 1/4 teaspoonfuls salt 1 teaspoonful sugar 1/2 teaspoonful mustard Cayenne 1 cupful vegetable oil
Into a mixing bowl put the eggs and vinegar. Mix well. Add the other ingredients. (It is not necessary to stir them.)