Grading Eggs.
Eggs are among the most difficult of food products to grade, because each egg must be considered separately and because the actual substance of the egg cannot be examined without destroying the egg. From external appearance, eggs can be selected for size, color, cleanliness of shell and freedom from cracks. This is the common method of grading in early spring when the eggs are uniformly of good quality.
Later in the season the egg candle is used. In the technical sense any kind of a light may be used as an egg candle. A sixteen candle power electric lamp is the most desirable. The light is enclosed in a dark box, and the eggs are held against openings about the size of a half dollar. The candler holds the egg large end upward, and gives it a quick turn in order to view all sides, and to cause the contents to whirl within the shell. To the expert this process reveals the actual condition of the egg to an extent that the novice can hardly realize. The art of egg candling cannot be readily taught by worded description. One who wishes to learn egg candling had best go to an adept in the art, or he may begin unaided and by breaking many eggs learn the essential points.
Eggs when laid vary considerably in size, but otherwise are a very uniform product. The purpose of the egg in nature requires that this be the case, because the contents of the egg must be so proportioned as to form the chick without surplus or waste, and this demands a very constant chemical composition.
For food purposes all fresh eggs are practically equal. The tint of the yolk varies a little, being a brighter yellow when green food has been supplied the hens. Occasionally, when hens eat unusual quantities of green food, the yolk show a greenish brown tint, and appear dark to the candler. Such eggs are called grass eggs; they are perfectly wholesome.
An opinion exists among egg men that the white of the spring egg is of finer quality and will stand up better than summer eggs. This is true enough of commercial eggs, but the difference is chiefly, if not entirely, due to external factors that act upon the egg after it is laid.
There are some other peculiarities that may exist in eggs at the time of laying, such as a blood clot enclosed with the contents of the egg, a broken yolk or perhaps bacterial contamination. "Tape worms," so-called by egg candlers, are detached portions of the membrane lining of the egg. "Liver spots" or "meat spots" are detached folds from the walls of the oviduct. Such abnormalities are rare and not worth worrying about.
The shells of eggs vary in shape, color and firmness. These variations are more a matter of breed and individual idiosyncrasy than of care or feed.
The strength of egg shells is important because of the loss from breakage. The distinction between weak and firm shelled eggs is not one, however, which can be readily remedied. Nothing more can be advised in this regard than to feed a ration containing plenty of mineral matter and to discard hens that lay noticeably weak shelled or irregularly shaped eggs.
Preference in the color of eggs shells is a hobby, and one well worth catering to. As is commonly stated, Boston and surrounding towns want brown eggs, while New York and San Francisco demand white eggs. These trade fancies take their origin in the circumstances of there being large henneries in the respective localities producing the particular class of eggs. If the eggs from such farms are the best in the market and were uniformly of a particular shade, that mark of distinction, like the trade name on a popular article, would naturally become a selling point. Only the select trade consider the color in buying.