Most of the preceding stews will serve also fairly as soups, by adding more water. Rub salt into meat for soups, but not for stews, as the salt extracts the juices; and in stews the meat is to be eaten, while in soups properly so called it is only the liquor that is served. Put meat into cold water for soups, as slowly heating also extracts the juices. For this same reason, meat that is boiled for eating should be put into boiling water to keep the juices in it.
Always skim often, as soon as the water begins to simmer; and do not add the salt and other seasoning till the scum ceases to rise.
Do not boil after the juices are extracted, as too much boiling injures the flavor.
Never cool soup in metal, as there may be poison in the soldering or other parts.
If you flavor your soup by vegetables, do not boil them in the soup, but in very little water, which is to be added to the soup with them, as it contains much of their flavor.
When onion is used for flavor, slice and fry it, and dredge on a little flour; add the water in which the vegetables for soup were boiled, or some meat broth, and then pour it into the soup. If you flavor with wine, soy, or catsup, put them into the tureen, and pour the soup upon them, as the flavor is lessened by putting them into the soup-kettle. Breadcrumbs, toast, or crackers also must be put in the tureen. Keep soup covered tight while boiling, to keep in flavors. If water is added, it must be boiling. The rule to guide in using salt and pepper is a heaping tea-spoonful of salt to a quart of water, and one-sixth as much pepper. But as tastes are different, and the salt and pepper vary in strength, the housekeeper can, on trial, change the recipe with a pencil, Soup stock is broth of any kind of meat prepared in large quantity, to keep on hand for gravies and soups. Beef and veal make the best stock. One hind shin of beef makes five quarts of stock, and one hind shin of veal makes three quarts. Wash and put into twice as much water as you wish to, to have soup, and simmer five or six hours.
All kinds of bones should be mashed and boiled five or six hours, to take out all the nutriment, the liquor then strained, and kept in earthenware or stone, not in tin. Take off the fat when cool.
Cool broth quickly, and it keeps longer.
Use a flat-bottom kettle, as less likely to scorch.
Soft water is best for soups; a little soda improves hard water.
Stock will keep three or four days in cool weather; not so long in warm. Keep it in a cool place. When used, heat to boiling point, and then take up and flavor.
Put in the salt and pepper when the meat is thoroughly done.
Meat soups are best the second day, if warmed slowly and taken up as soon as heated. If heated too long, they become insipid.
Thin soups must be strained. If to be made very clear, stir in one or two well beaten eggs, with the shells, and let it boil half an hour.
Use the meat of the soup for a hash, warmed together with a little fat, and well seasoned.
Be very careful, in using bones and cold meats for soups, that none is tainted, for the soup may be ruined by a single bit of tainted meat or bone.