This section is from the book "The Boston Cooking-School Cook Book", by Fannie Merritt Farmer. Also available from Amazon: Original 1896 Boston Cooking-School Cook Book.
Proteid, 14.9% Fat, 10.6%
Mineral matter, 1 % Water, 73.5%
EGGS, like milk, form a typical food, inasmuch as they contain all the elements, in the right proportion, necessary for the support of the body. Their highly concentrated, nutritive value renders it necessary to use them in combination with other foods rich in starch (bread, potatoes, etc.). In order that the stomach may have enough to act upon, a certain amount of bulk must be furnished.
A pound of eggs (nine) is equivalent in nutritive value to a pound of beef. From this it may be seen that eggs, at even twenty-five cents per dozen, should not be freely used by the strict economist. Eggs being rich in proteid serve as a valuable substitute for meat. In most families, their use in the making of cake, custard, puddings, etc., renders them almost indispensable. It is surprising how many intelligent women, who look well to the affairs of the kitchen, are satisfied to use what are termed "cooking eggs"; this shows poor judgment from an economical standpoint. Strictly fresh eggs should always be used if obtainable. An egg after the first twenty-four hours steadily deteriorates. If exposed to air, owing to the porous structure of the shell, there is an evaporation of water, air rushes in, and decomposition takes place.
White of egg contains albumen in its purest form. Albumen coagulates at a temperature of from 134° to 160° F. Herein lies the importance of cooking eggs at a low temperature, thus rendering them easy of digestion. Eggs cooked in boiling water are tough and horny, difficult of digestion, and should never be served.
When eggs come from the market, they should be washed, and put away in a cold place.
Ways of Determining Freshness of Eggs. I. Hold in front of candle flame in dark room, and the centre should look clear.
II. Place in basin of cold water, and they should sink.
III. Place large end to the cheek, and a warmth should be felt.
Ways of Keeping Eggs. I. Pack in sawdust, small end down.
II. Keep in lime water.
III. From July to September a large number of eggs are packed, small ends down, in cases having compartments, one for each egg, and kept in cold storage. Eggs are often kept in cold storage six months, and then sold as cooking eggs.
Have ready a saucepan containing boiling water. Carefully put in with a spoon the number of eggs desired, covering them with water. Remove saucepan to back of range, where water will not boil. Cook from six to eight minutes if liked "soft-boiled," forty to forty-five if liked "hard-boiled." Eggs may be cooked by placing in cold water and allowing water to heat gradually until the boiling-point is reached, when they will be "soft boiled." In using hard-boiled eggs for making other dishes, when taken from the hot water they should be plunged into cold water to prevent, if possible, discoloration of yolks.
Eggs perfectly cooked should be placed and kept in water at a uniform temperature of 175° F.
 
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