Eggs
A s will be seen from the analysis given below, an egg is particularly rich in nitrogenous elements. It is indeed one of the most highly concentrated forms of nitrogenous food, about one third of its weight being solid nutriment, and for this reason is often found serviceable in cases of sickness where it is desirable to secure a large amount of nourishment in small bulk.
Composition of the white of an ordinary hen's egg.
| Nitrogenous matter | 20.4 |
| Fatty matter | 10.0 |
| Mineral matter | 1.6 |
| Water | 68.0 |
Composition of the yolk.
| Nitrogenous matter | 1.0 |
| Fatty matter | 30.7 |
| Mineral matter | 1.3 |
| Water | 52.0 |
The white of egg is composed mainly of albumen in a dissolved state, inclosed in layers of thin membrane. When beaten, the membranes are broken, and the liberated albumen, owing to its viscous or glutinous nature, entangles and retains a large amount of air, thus increasing to several times its original bulk.
The yolk contains all the fatty matter, and this, with a modified form of albumen called vitellin, forms a kind of yellow emulsion. It is inclosed in a thin membrane, which separates it from the surrounding white.
The yolk, being lighter than the white, floats to that portion of the egg which is uppermost, but is held in position by two membranous cords, one from each end of the egg. The average weight of an egg is about two ounces, of which ten per cent consists of shell, sixty of white, and thirty of yolk.
How to Choose Eggs.—The quality of eggs varies considerably, according to the food upon which the fowls are fed. Certain foods communicate distinct flavors, and it is quite probable that eggs may be rendered unwholesome through the use of filthy or improper food; hence it is always best, when practicable, to ascertain respecting the diet and care of the fowls before purchasing eggs.
On no account select eggs about the freshness of which there is any reason to doubt. The use of stale eggs may result in serious disturbances of the digestive organs.
An English gentleman who has investigated the subject quite thoroughly, finds upon careful microscopical examination that stale eggs often contain cells of a peculiar fungoid growth, which seems to have developed from that portion of the egg which would have furnished material for the flesh and bones of the chick had the process of development been continued. Experiments with such eggs upon dogs produce poisonous effects.
There are several ways of determining with tolerable accuracy respecting the freshness of an egg. A common test is to place it between the eye and a strong light. If fresh, the white will appear translucent, and the outline of the yolk can be distinctly traced. By keeping, eggs become cloudy, and when decidedly stale, a distinct, dark, cloud-like appearance may be discerned opposite some portion of the shell. Another test is to shake the egg gently at the ear; if a gurgle or thud is heard, the egg is bad. Again, eggs may be tested by dropping into a vessel containing a solution of salt and water, in the proportion of a tablespoonful to a quart. Newly laid eggs will sink; if more than six days old, they will float in the liquid; if bad, they will be so light as to ride on the surface of the brine. The shell of a freshly laid egg is almost full; but owing to the porous character of the shell, with age and exposure to air a portion of the liquid substance of which the egg is composed evaporates, and air accumulates in its place at one of the extremities of the shell. Hence an egg loses in density from day to day, and the longer the egg has been kept, the lighter it becomes, and the higher it will rise in the liquid.
An egg that will float on the surface of the liquid is of too questionable a character to be used without breaking, and is apt to be unfit for use at all.
How to Keep Eggs.—To preserve the interior of an egg in its natural state, it is necessary to seal the pores of the shell air-tight, as the air which finds its way into the egg through the pores of the shell causes gradual decomposition. Various methods are devised to exclude the air and thus preserve the egg. A good way is to dip perfectly fresh eggs into a thick solution of gum-arabic,—equal parts of gum and water,—let the eggs dry and dip them again, taking care that the shells are entirely covered with the solution each time. When dry, wrap separately in paper and pack in a box of sawdust, bran, salt, or powdered charcoal, and cover tightly to keep out the air.
There is a difference of opinion as to which end should be placed down in packing; most authorities recommend the smaller end. However, an experienced poultryman offers the following reasons for packing with the larger end down: "The air-chamber is in the larger end, and if that is placed down, the yolk will not break through and touch the shell and thereby spoil. Another thing: if the air-chamber is down, the egg is not so liable to shrink away."
It would be well for housekeepers to make the test by packing eggs from the same lot each way and noting the result.
Melted wax or suet may be used to coat the shells. Eggs are sometimes immersed and kept in a solution of lime water, a pound of lime to a gallon of cold water, or simply packed in bran or salt, without a previous coating of fat or gum. By any of these methods they will keep for several weeks. Eggs, however, readily absorb flavors from surrounding substances, and for that reason lime water or salt solution are somewhat objectionable. Nothing of a disagreeable odor should be placed near eggs.
Eggs for boiling may be preserved by placing in a deep pan, and pouring scalding water over them. Let them stand half a minute, drain off the water, and repeat the process two or three times. Wipe dry, and when cool, pack in bran.
Eggs should be kept in a cool, not cold, place and handled carefully, as rough treatment may cause the mingling of the yolk and white by rupturing the membrane which separates them; then the egg will spoil quickly.
The time required for the digestion of a perfectly cooked egg varies from three to four hours.
It is generally conceded that eggs lightly cooked are most readily digested. What is generally termed a hard-boiled egg is not easily acted upon by the digestive juices, and any other manner of cooking by which the albumen becomes hardened and solid offers great resistance to digestion.
To Beat Eggs.—This may seem trivial, but no dish requiring eggs can be prepared in perfection, unless they are properly beaten, even if every other ingredient is the best. An egg-beater or an egg-whip is the most convenient utensil for the purpose; but if either of these is not to be had, a silver fork will do very well, and with this the beating should be done in sharp, quick strokes, dipping the fork in and out in rapid succession, while the egg should grow firmer and stiffer with every stroke. When carelessly beaten, the result will be a coarse and frothy instead of a thick and cream-like mass. Use a bowl in beating eggs with an egg-beater, and a plate when a fork or egg-whip is employed.
If the white and yolk are used separately, break the shells gently about the middle, opening slowly so as to let the white fall into the dish, while retaining the yolk in one half of the shell. If part of the white remains, turn the yolk from the one half to the other till the white has fallen. Beat the yolks until they change from their natural orange color to a much lighter yellow. The whites should be beaten until firm and dry enough not to fall from the bowl if turned upside down. The yolk should always be beaten first, since, if the white is left to stand after being beaten, a portion of the air, which its viscous nature allows it to catch up, escapes and no amount of beating will render it so firm a second time. Eggs which need to be washed before breaking should always be wiped perfectly dry, that no water may become mingled with the egg, as the water may dilute the albumen sufficiently to prevent the white from becoming firm and stiff when beaten.
In cold weather, it is sometimes difficult to beat the whites as stiff as desirable. Albumen is quite susceptible to temperature, and this difficulty may be overcome by setting the dish in which the eggs are beaten into warm water—not hot by any means—during the process of beating. In very hot weather it is often advantageous to leave the eggs in cold or ice water for a short time before beating. When a number of eggs are to be used, always break each by itself into a saucer, so that any chance stale egg may not spoil the whole. If the white or yolk of an egg—is left over, it may be kept for a day or two if put in a cool place, the yolk thoroughly beaten, the white unbeaten.