Chapter 8

21. If nothing has been done to preserve eggs, the simple test for freshness illustrated in Fig. 3, which consists in placing the eggs in a glass containing water, will be found effective. A perfectly fresh egg will sink when it is put into the water, but if the egg is 3 weeks old the broad end will rise slightly from the bottom of the glass. An egg that is 3 months old will sink into water until only a slight portion of the shell remains exposed; whereas, if the egg is older or stale, it will rise in the water until nearly half of it is exposed. 22. The test known as candling, which is usually applied to eggs before they are put on the market, can also be practiced by the housewife in the home. This method of determining the freshness of eggs consists in placing a piece of cardboard containing a hole a little smaller than an egg between the eye and a light, which may be from a lamp, a gas jet, or an electric light, and holding the egg in front of the light in the manner shown in Fig. 4. The rays of light passing through the egg show the condition of the egg, the size of its air space, and the growth of mold or the spoiling of the egg by any ordinary means.

In Fig. 5 is shown how an egg at various stages of freshness appears when candled. When an egg is fresh, it will appear as in (_a_); that is, the yolk will be barely distinguishable from the white except as a slightly darker area in the center of the egg, and the entire egg will appear clear and bright and free from spots. In an egg that is a little older, candling will reveal a slightly darker yolk, a cloudy white, and a larger air space, as in (_b_). In a watery egg, or one that is beginning to spoil, various dark spots and blotches usually develop, as view (_c_) indicates. When an egg is rotten, the contents of the shell will look dark in candling and the yolk will appear to be mixed with the white, as in (_d_). 23. If the housewife does not wish to resort to candling, she may determine the condition of an egg by breaking it into a saucer and examining it carefully. If the egg is newly laid, no odor will be detected and the white will be clear, elastic, and rather thick; also, where it joins the yolk it will be almost solid. The yolk of such an egg will have an even yellow color, without lighter or darker spots and, as shown in Fig. 6 (_a_), will stand up well from the surface of the white. Sometimes a small spot of blood may be detected on the yolk of a perfectly fresh egg, but, while this is not pleasant to look at, it does not affect the quality of the egg. When an egg that is not real fresh is broken into a saucer, the yolk will lie flat, as in (_b_). In an egg that is quite stale, the membrane surrounding the yolk is easily destroyed, so that even when such an egg is broken carefully the yolk and the white are likely to run together.

* * * * *

PRESERVATION OF EGGS

CAUSES AND PREVENTION OF DETERIORATION

24. As has been implied in the discussion given thus far, eggs will deteriorate or spoil in a comparatively short time unless something is done to preserve them. In view of the eggs she keeps on hand at home, as well as those she buys, the causes of spoiling and the ways in which to prevent spoiling are matters with which the housewife should be familiar, particularly if she would secure for her family eggs of the best quality at prices that are not beyond her means. The spoiling of eggs is due to decomposition, which is caused by molds or bacteria that result from accidental causes, and, in fertile eggs, to the germination and development of the chick, which is a natural process. The loss of quality resulting from molds and bacteria in the egg is brought about by their growth and by the formation of chemical compounds, which give spoiled eggs their peculiar appearance, taste, and odor. Some of these molds are not injurious to health, while others may give rise to more or less serious illness.

25. Various methods have been devised whereby their rapid deterioration may be prevented, and a knowledge of these is important to those who have occasion to purchase eggs or to keep them over from the season of plenty to the season of scarcity. The method followed to prevent losses due to the development of the embryo consists in the production of infertile eggs--that is, eggs that are non-productive. This is a point that is as well worth remembering in the home production of eggs as it is in professional poultry raising. The method employed to prevent the infection of eggs by molds and bacteria is to keep them clean and dry from the time they are laid until they are finally used.

26. While the preservation of eggs is carried on to a greater extent at present than formerly, the idea is neither new nor original; indeed, it has been practiced for many years by the people of some foreign countries. For instance, in some sections of China, duck eggs are preserved by covering them with a layer of mud, and such eggs are often kept for a year or more before they are eaten. However, eggs stored in this way decompose and their odor and flavor disappear before they are used, so that they must usually be hard boiled before they can be eaten. Egg preservation such as is practiced in the United States is the opposite of this and attempts to prevent not only ripening processes and putrefactive changes but any bacterial or other changes that lessen the original quality. It will be well to note, however, that eggs preserved for any length of time deteriorate to some extent and cannot be expected to be equally as good as fresh eggs.

COMMERCIAL PRESERVATION OF EGGS

27. The usual market method of preserving eggs is by cold storage, an industry that has developed to vast proportions in recent years. The success of this method depends on the fact that germs causing decomposition will not live in a low temperature. While the plan of storing eggs is responsible for their high price at certain times, it is also a means of supplying eggs to many persons who would otherwise not be able to obtain them. The greatest point in favor of this plan, however, is that it makes possible the marketing of quantities of eggs during the winter season of scarcity at a price that, although somewhat high at times, is much more moderate than it would be if it were not possible to store eggs in large quantities.

28. In order that advantage may be taken of favorable climatic conditions, eggs are commonly purchased for storage as early in the year as they are abundant. They are selected with great care, only those which are clean, sound, and fresh being used. These eggs are packed in clean cases, and then placed in warehouses where they are kept at a temperature just above freezing, or one that ranges from 32 to 40 degrees Fahrenheit. In such storage, precaution is usually taken to prevent the eggs from freezing, for while freezing does not necessarily injure them for immediate use it breaks the shell because of the contraction that occurs. While the eggs are in storage, they are also protected as far as possible from air circulation, as this increases evaporation and causes the contents of eggs to shrink. To prevent the yolks from settling to one side, and finally adhering to the shell, the eggs are turned frequently. The usual limits of storage are from 6 to 9 months, but eggs are not generally allowed to remain in storage more than 8 months. When taken out at the end of that time, it will be found that they have deteriorated very little, and while they cannot compete with the better grades of fresh eggs, they are as desirable as most of the eggs that can be purchased in the early fall when eggs are not plentiful.

29. Sometimes eggs are removed from the shells, stored for commercial use in containers of about 50 pounds each, and kept at the freezing point until they are to be used. Eggs in this form, which may be bought with the yolks and whites either mixed or separate, find a ready market in bakeries and restaurants, where large quantities of eggs are continually used. Such eggs remain good for any length of time while they are kept frozen, but they must be used immediately after they are removed from storage.

30. It is not always necessary to keep eggs at a cold temperature in order to preserve them, for a method that has proved very satisfactory is to reduce them to the form of powder by drying them. In this form, the bulk is greatly reduced, 1 pound of the dry material representing 30 to 40 eggs, and in order to prepare them for use in cooking they must be mixed with water. POWDERED EGGS, or _desiccated eggs_, as they are usually called, can be kept for an indefinite length of time without special care in storage, when they are wholesome and carefully handled. Tests that have been made show that eggs of this kind give fairly good results when used in cookery, but they are used principally by bakers, for they can be obtained more cheaply than fresh eggs, especially when it is difficult to secure eggs in other forms.

HOME PRESERVATION OF EGGS

31. The housewife who desires to run her household on an economical basis will not depend entirely on eggs that are commercially stored, but will take advantage of one of the many methods by which eggs may be successfully kept in the home. By being prudent in this matter, she will be prepared to supply her family with this commodity at times when the market price is high.

As many as twenty household methods have been tried out for the preserving of eggs, but each one is based on the theory that decay is hindered when the shell is covered with some substance that renders it air-tight and prevents evaporation or the entrance of bacteria and mold. Among the methods that have met with the most success are burying eggs in oats, bran, or salt; rubbing them with fat; dipping them in melted paraffin; covering them with varnish or shellac; and putting them down in lime water or in a solution of water glass.

No matter which of these methods is adopted, however, it will be well to note that only eggs laid in April, May, or June should be used for storage purposes, as these are the best ones laid during the year; also, that the eggs should always be packed with the small end down, because the yolk will not settle toward the small end so readily as toward the large end or the side.

32. Of these various ways of preserving eggs in the home, probably the oldest method is that of packing the eggs in oats, bran, or salt. This method is fairly effective, but the eggs preserved by it do not keep so long as eggs preserved by other methods, nor is their quality so good. Preserving eggs by completely covering the shells with fat, vaseline, paraffin, varnish, or other substance that will exclude the air but not impart flavor to the eggs, proves a more satisfactory method so far as the eggs are concerned, but it requires more time and handling. To assist in their preservation, eggs are sometimes immersed in boiling water for 12 to 15 seconds. This process, which causes the white to harden slightly just inside of the shell, keeps the eggs fairly well, but it is rather difficult to accomplish, as the least overcooking renders the egg unfit for use as a raw egg.

As a result of many trials, it has been found that putting eggs down in the various solutions that are used for this purpose is the most effective way of preserving them under home conditions, provided, of course, the solutions in which the eggs are immersed do not flavor the eggs. Therefore, to assist the housewife, detailed directions for using lime water and water glass for this purpose are here given.

33. PRESERVATION WITH LIMEWATER.--To prepare limewater for the preservation of eggs, dissolve 1 pound or 1 pint of salt and 1 quart of finely slaked lime in 3 gallons of water, stir the solution at frequent intervals for a day or two, and then allow the liquid to settle. Place the eggs in tall stone crocks or kegs with their pointed ends turned down, filling the receptacles to within a few inches of the top. Pour the clear limewater over the eggs so arranged, allowing it to rise an inch or two above the top layer. Then stand the vessel in a cool place where the temperature will not exceed 50 degrees Fahrenheit. Eggs so treated will keep for at least 6 or 8 months. The only objection to this plan is that the eggs preserved by it sometimes acquire a slight lime taste.

34. PRESERVATION WITH WATER GLASS.--Putting eggs down in a solution of water glass is without doubt the most satisfactory method of storing them in the home. So effective does this method prove that the housewife who has a convenient and proper storage room should not fail to take advantage of this way of laying up a supply of eggs.

The commercial form of water glass is usually a mixture of potassium and sodium silicate, which, besides being cheaper than that which is chemically pure, is the kind that is preferred for the purpose of preserving eggs. A good quality of it either in a sirup-like solution or in the form of a powder retails in drug or grocery stores for about 10 cents a pound. To make a solution of the desired strength to preserve eggs satisfactorily, dissolve 1 part of water glass in 7 parts of warm water that has first been boiled to drive off bacteria, mold, spores, etc. One quart of water glass will make sufficient solution to cover about 12 dozen eggs. With the solution thoroughly mixed, it is ready to pour over the eggs.

In selecting eggs for the purpose of storing, be careful to choose only those which are clean, fresh, and perfectly sound, and, if possible, infertile. It is advisable not to wash them before they are put into the preservative, for they will keep better if their bloom is not removed. Place the eggs in receptacles in the manner explained for preserving eggs in limewater, and over them pour the water-glass solution until they are all covered. If the eggs so prepared are stored in a cool place, they will keep as long as those preserved in limewater; besides, there will be no danger of their acquiring any foreign flavor.

* * * * *

COOKING OF EGGS

PRELIMINARY PREPARATION

35. The successful preparation of eggs for their use as a food demands that certain points must be observed by the housewife. For instance, she must see that the eggs she uses are in the right condition; that the shells are properly broken for the most convenient removal of the egg; that the parts of the egg are separated in the right way in case the whites and the yolks are to be used separately; and that the eggs receive the right treatment for the purpose for which they are to be used. Attention to all these points not only will insure the most satisfactory results, but will enable the housewife to supply her family with food that is extremely wholesome and nutritious.

36. Exterior Condition of Eggs.--As has been explained, clean eggs are the most desirable, but it is not advisable to wash eggs that are to be kept for even a short time, as washing them removes the natural coating that helps to prevent the entrance of bacteria. However, as it is necessary that the shells be perfectly clean before they are broken or before the eggs are cooked, the eggs may be washed or wiped with a damp cloth immediately before such processes.

37. BREAKING OF EGGS.--In cookery, it is usually desirable to break an egg shell so that the yolk will not run into the white; that is, so that these can be kept separate. While there are several methods of doing this, the housewife should adopt the one that is most convenient for her. A quick method that is often employed consists in striking the shell on the edge of the pan or the bowl into which the contents are to be put. A preferable method, however, is illustrated in Fig. 7. It consists in striking one side of the shell, midway between the ends, a sharp blow with the edge of a knife. The advantage of this method will be evident after a trial or two, for it will be found that the depth of the cut made by the knife can be so gauged that there will be little danger of breaking the yolk. Besides, fragments of the shell are not likely to fall into the bowl or the pan with the contents of the egg.

38. SEPARATING OF EGGS.--Frequently recipes require that the yolks and whites of eggs be beaten separately before being added to the other ingredients. When this is the case, care must be exercised in taking the egg from the shell. The method by which this is most easily accomplished is illustrated in Fig. 8. As will be observed, the shell is first broken as nearly as possible into halves and then, while the egg is poured from 1/2 of the shell into the other, the white is dropped into a dish and the yolk is retained in the shell. During this process, the yolk should remain intact in its delicate membrane, for if it becomes mixed with the white the lightness of the white will be injured. To separate the yolk from the white is not difficult when eggs are fresh, but as they become stale the membrane surrounding the yolk grows weak and breaks easily. If the yolk breaks and any of it falls into the white, it must be completely removed before the white is beaten.

39. BEATING OF EGGS.--Sometimes eggs are cooked in the shell and other times they are used alone just as they are removed from the shell, as in the frying and poaching processes; however, when they are to be combined with other ingredients, they are usually beaten. Eggs are beaten for the purpose of mixing the yolk and the white or of incorporating air to act as a leavening agent when the eggs are heated in the cooking process. Various utensils, such as a fork, an egg whip, or an egg beater, may be employed for beating eggs, the one to select depending on the use to which the eggs are to be put. The rotary, or Dover, egg beater, previously described as a labor-saving device and illustrated in Fig. 9 (_a_), should be used to beat either whole eggs or the yolks of eggs when they are to be used in custards, mayonnaise, cakes, puddings, etc., as it will beat them sufficiently light for such purposes. However, for the beating of egg whites, use should be made of a fork or of an egg whip similar to that shown in (_b_), because the whites must be lifted instead of stirred for the incorporation of air, and it is only with a utensil of this kind that this can be accomplished. Then, too, more air can be incorporated into the whites and the volume of the egg thereby increased by means of a fork or an egg whip than by an egg beater. An important point to remember in this connection is that eggs can be beaten more successfully when they are cold and have had a pinch of salt added to them.

40. In the beating of eggs, it should be remembered that for some purposes, as in making some kinds of sponge cake, they are beaten until nearly frothy, as shown in Fig. 10, when they do not stand up nor cling to the whip; whereas, for other purposes, as in making meringue, they are beaten until they are stiff enough to stand up well and to adhere to the whip, as Fig. 11 shows. When egg whites are to be beaten stiff, care should be taken not to continue the beating too long. If this is done, they will become dry and will break up into small pieces, a condition that will mean a loss of some of the air that has been incorporated. It is well also to observe that egg whites should always be beaten in the same direction and that the same motion should be continued throughout the beating, for a change of direction or motion always causes a loss of air. A final precaution to take is never to allow egg whites to stand after they are beaten. If this is done, the leavening power of the eggs is reduced, because the air soon escapes from beaten eggs and leaves underneath them a clear liquid that can never be beaten up. For instance, eggs that are to be used for boiled icing should not be beaten until the sirup has finished boiling. However, eggs that have been separated but not beaten may stand for a couple of hours, provided they are covered and kept in a cool place.

POINTS TO OBSERVE IN COOKING EGGS

41. As has been previously stated, the substance in eggs that requires special care in the cooking process is the protein, which occurs in this food in the form of albumen. Because of this, certain points concerning the treatment that the albumen requires should be kept in mind. In a raw egg, the albumen occurs in a semiliquid form, but it coagulates at a lower temperature than does the yolk, which contains a high percentage of fat. After coagulation, the consistency of the two parts is very different. The white is elastic and more or less tough, while the yolk, upon being thoroughly cooked, becomes powdery, or mealy, and breaks up into minute particles. The egg white begins to coagulate at 134 degrees Fahrenheit, and it becomes white and jellylike at 160 degrees. Bringing an egg to such a temperature produces a more desirable result than cooking it at a high temperature--boiling point, for instance--because the albumen, instead of becoming tough, as it does at a high temperature, acquires a soft, tender consistency that exists throughout the entire egg. An egg cooked in this way is more digestible and appetizing than one that is boiled until it becomes hard and tough.

42. The low temperature at which eggs will cook in the shell applies also to eggs when they are combined with other foods. Sometimes, however, a mixture in which eggs are one of the ingredients must be cooked at a high temperature because the materials mixed with them require it. This difficulty can be overcome when eggs are combined with starchy foods, such as corn starch, rice, and tapioca, that require long cooking. In such a case, all the ingredients except the eggs may be cooked the length of time they require, after which the eggs may be added so that they will cook just long enough to become coagulated. Longer cooking is liable to spoil the texture. Often the starchy mixture retains sufficient heat to set the eggs without further cooking after they are added.

43. A very nutritious way in which to prepare eggs when they are to be used for a dessert is to combine them with milk to form a custard, which, after being sweetened and flavored, is baked. The proportion that has been accepted as ideal to produce a dessert of the right thickness is one egg to each cupful of milk; however, an entire egg is not always required, as one yolk is often sufficient to thicken 1 cupful of milk. Care should be taken in the cooking of such custards, for if they are cooked too long or at too high a temperature they will curdle and whey; whereas, a properly cooked custard--that is, one cooked slowly at a low temperature and for the required length of time--will have a smooth, jellylike consistency. A slight variation in a dish of this kind is secured by reducing the number of eggs and thickening it with corn starch or some other starchy material. While such a mixture is not a true custard, it makes an excellent dessert.