This section is from the book "Elements Of The Theory And Practice Of Cookery", by Mary E. Williams. Also available from Amazon: Elements Of The Theory And Practice Of Cookery; A Textbook Of Domestic Science For Use In Schools.
1. Have all trimmings sent home by the butcher to be used in making stock.
2. On account of its strong, fatty flavor, avoid using much mutton in stock containing other meat.
4. Stock made without vegetables keeps best in hot weather. When taking out a portion of such stock for soup, add for each pint of it one heaping tablespoonful of each vegetable included in the Directions for Making Soup-stock, cook them in it one hour, and strain.
5. A little salt helps to preserve stock, but it must be used sparingly at first, because the stock grows Salter as it lessens by evaporation.
6. Do not try to extract the last bit of gelatin from bones; too long boiling gives stock a flavor of glue.
7. If you must use the stock the day it is made, skim off what fat you can, and remove the rest as completely as possible with absorbent paper, or with a bit of ice wrapped in cloth. The fat hardens on the cloth and can be scraped off.
8. Cook vegetables, macaroni, and other materials to be served in soup in a small quantity of stock, and add this with them to the portion to be served. If, however, the stock is weak, so that it would be improved by boiling down, cook this material in the whole quantity to be sent to table.
9. Stock used instead of water in meat sauces, gravies, and stews makes them richer. By boiling meat in stock the stock itself is enriched.
In spite of care in keeping soup-stock below the boiling-point, some albumin coagulates, a part of which settles and a part rises as scum. Skimming off this scum lessens the food value of the soup, already small; soup, both skimmed and cleared, is a stimulant merely, still, for the sake of appearances, a perfectly clear soup is sometimes desired.
Put into a saucepan the stock to be cleared, and into it stir the whites and crushed shells of as many eggs as there are quarts of stock. Heat and stir until it has boiled for two minutes; then keep it hot, without letting it simmer, for twenty minutes, in order that the albumin, as it coagulates, may entangle every solid particle in the stock. Pour through a fine strainer held above double cheese-cloth laid over another strainer. The first strainer keeps the scum from clogging the cloth.